Apparatus and method comprising deformable lens element

ABSTRACT

An apparatus comprising a deformable lens element can be provided wherein a deformable lens element can be deformed to change an optical property thereof by the impartation of a force to the deformable lens element.

CROSS REFERENCE TO RELATED APPLICATIONS

This application claims priority under 35 U.S.C. §119(e) to ProvisionalPatent Application No. 60/875,245, entitled “Focus Module and ComponentsWith Actuator Polymer Control,” filed Dec. 15, 2006 and to ProvisionalPatent Application No. 60/961,036 entitled “Variable Lens Elements AndModules,” filed Jul. 18, 2007. The above provisional patent applicationsare incorporated herein by reference.

FIELD OF THE INVENTION

The invention relates to a lens element for incorporation into anoptical imaging system and specifically to an apparatus and methodcomprising a deformable lens element.

BACKGROUND OF THE INVENTION

Variable lenses, e.g., multiple focus lenses and zoom lenses havetraditionally employed one or more non-deformable (i.e., rigid such asglass or polycarbonate) lens elements which are moved along an imagingaxis by forces often supplied by a motor.

In recent years, motorless electro-responsive lens elements haveattracted increased attention of researchers and designers of opticalsystems. One type of motorless electro-responsive lens element is the“fluid lens” lens element which generally includes a rigid orelastomeric membrane filled with one or more fluids having indices ofrefraction greater than 1. Fluid lens element technology has attractedthe attention of many designers of optical systems who generally seetraditional solid lens elements and motor equipped systems as bulky andenergy hungry. With the proposals for fluid lens elements there havebeen proposed various methods for varying an optical property of a fluidlens element for integration into an optical system. Where fluid lenselements have been proposed, the proposed alternatives for varyingoptical properties of such lens elements can be categorized into twobroad categories: electro wetting and fluid injection.

According to a process of electro wetting, a fluid lens element isprovided having at least two immiscible fluids and a voltage is appliedto the fluid lens element. A surface tension of the fluid lens elementchanges as a result of the voltage being applied, bringing about achange in the curvature of an interface between the at least two fluids.

According to a process of fluid injection, a pump is provided adjacent afluid lens element which pumps in and draws out fluid from the lenselement. As fluid is pumped in and drawn out of the lens element,optical properties of the lens element change.

Problems have been noted with both the electro wetting and fluidinjection methods for varying an optical property of a fluid lenselement. Regarding electro wetting, one problem that has been noted isthat the electrical current repeatedly flowing through the lens elementtends to alter the characteristics of the lens element over time,rendering any system in which the lens element is employed unreliableand unpredictable. Another problem noted with proposals involvingelectro wetting is that electro wetting normally involves providing twotypes of fluids. As the reference index difference between the fluids issmall, the power of the lens element is reduced.

Regarding the fluid injection methods, the pumps for providing suchfluid injection are necessarily complex and intricate making areasonably costly system and acceptable miniaturization difficult toachieve.

Because of the problems noted with both the electro wetting and fluidinjection methods for varying an optical property of a deformable lenselement, designers of commercially deployed optical systems continue torely almost exclusively on traditional motor-actuated rigid lenselements in the design of optical systems. Yet, the miniaturization andenergy conservation achievable with motor-actuated rigid elementequipped optical systems continues to be limited.

SUMMARY OF THE INVENTION

An apparatus comprising a deformable lens element can be providedwherein a deformable lens element can be deformed to change an opticalproperty thereof by the impartation of a force to the deformable lenselement.

DETAILED DESCRIPTION OF THE DRAWINGS

The features described herein can be better understood with reference tothe drawings described below. The drawings are not necessarily to scale,emphasis instead generally being placed upon illustrating the principlesof the invention. In the drawings, like numerals are used to indicatelike parts throughout the various views.

FIG. 1 is an exploded assembly view of a focus apparatus (focusingmodule) including a deformable lens element that is arranged in suchmanner that the deformable lens element can be deformed to vary anoptical characteristic of the lens element.

FIG. 2 is an assembled view of the focus apparatus of FIG. 1, showingthe apparatus in a state in which the deformable lens element includes aconvex lens surface.

FIG. 3 is an assembled view of the focus apparatus of FIG. 1 showing theapparatus in a state in which the deformable lens element includes anominally planar surface.

FIG. 4 is a cutaway side view showing an alternative embodiment of thedeformable lens element of FIGS. 1-3.

FIG. 5 is a cutaway side view showing an alternative embodiment of thedeformable lens element of FIGS. 1-3.

FIG. 6 is an exploded perspective assembly view of a focus apparatusincorporating a dielectric electro-active polymer actuator.

FIG. 7 is an exploded perspective view of a focus apparatusincorporating a deformable lens element and a hollow stepper motor.

FIG. 8 is a cutaway side view of the focusing apparatus as shown in FIG.7.

FIG. 9 is a perspective view illustrating operation of a hollow steppermotor in one embodiment.

FIG. 10 is an exploded perspective assembly view of a deformable lenselement in one embodiment.

FIG. 11 is an assembled cutaway side view illustrating the deformablelens element shown in FIG. 10.

FIG. 12 is a detailed cutaway side view illustrating a highlightedsection of the deformable lens element as shown in FIG. 10.

FIG. 13 is an assembled side view illustrating a deformable lens elementhaving a pair of opposing light entry and light exit lens surfaces thatcomprise respective deformable membranes.

FIG. 14 is an assembled side view showing an embodiment of a focusingapparatus incorporating a deformable lens element as shown in FIG. 13, afirst actuator for deforming a first deformable lens surface of thedeformable lens element and a second actuator for deforming a seconddeformable lens surface of the deformable lens element.

FIG. 15 is an assembled side view of a deformable lens elementincorporating a resiliently deformable material member.

FIG. 16 is an assembled side view of another embodiment of a deformablelens element incorporating a resiliently deformable material member.

FIG. 17 is a side view of a deformable lens element including aresiliently deformable material member and a protective coating thereon.

FIG. 18 is an assembled side view of a focus apparatus having adeformable lens element and a pair of flexible member actuators, whereinthe flexible members are adapted to substantially conform to the shapeof the deformable lens element.

FIG. 19 is an exploded perspective assembly view of a focus apparatus asshown in FIG. 18.

FIG. 20 and FIG. 21 are force impartation diagrams illustratingexemplary force impartation positions for a deformable lens member,showing front views of a deformable lens element looking in thedirection of an imaging axis.

FIGS. 22-24 are side schematic views illustrating various lensassemblies incorporating at least one deformable lens element.

FIG. 25 is an electrical block diagram of an exemplary imaging terminalin which a deformable lens element can be incorporated.

FIG. 26 is a timing diagram for illustrating exemplary aspects ofoperation of an imaging terminal in one embodiment.

FIG. 27 is a flow diagram illustrating an auto-focus algorithm that canbe executed by an imaging terminal in one embodiment.

FIG. 28 is a front perspective view of a hand held mobile terminalhaving a hand held housing in which the components as shown in FIG. 25can be incorporated and supported by.

DETAILED DESCRIPTION OF THE INVENTION

There is described herein in one embodiment a deformable lens elementfor incorporation into an optical imaging system, wherein a force can beimparted to a surface of the deformable lens element for varying of anoptical property of the lens element. There is accordingly, alsodescribed herein a method for varying an optical property of an opticalimaging system including the steps of incorporating a deformable lenselement into an optical imaging system; and imparting a force to asurface of the lens element for varying an optical property of the lenselement. With the described apparatus and method, infinitesimal changesin a deformable lens element's shape can result in large variation of adeformable lens element's optical properties.

The described deformable lens element apparatus and method provide anumber of advantages. For example, relative to presently availableoptical systems incorporating exclusively non-deformable (rigid) lenselements, the presently described apparatus and method providessignificant changes in optical properties while significantly reducingthe amount of movement of a lens element required to produce the desiredchange in optical property (e.g., focal length). By significantlyreducing the amount of movement of a lens element for producing adesired change in optical property, the described apparatus and methodfacilitate increased miniaturization of an imaging system, and decreasedenergy consumption of a designed optical system. The above advantagesare provided in a highly reliable, easily manufactured optical systemthat does not exhibit the reliability and manufacturing complexitydisadvantages associated with previously proposed electro wetting andfluid injection fluid lens based optical systems.

Various apparatuses are described herein having a deformable lenselement that can be deformed by application of a force to an externalsurface thereof. An illustrative embodiment of a described apparatus andmethod is shown in FIG. 1. In the embodiment of FIG. 1, a deformablelens element 10 is provided by the combination of deformable membrane 3,spacer element 2, and boundary element 1 which can be provided by apiece of non-deformable glass, and a focus fluid (not shown) or otherdeformable substance (e.g., a resiliently deformable volume) having anindex of refraction greater than 1. The focus fluid or other deformablesubstance can be disposed within cavity 8 (as seen in FIGS. 2 and 3)defined by the combination of deformable membrane 3, spacer element 2,and transparent boundary element 1 as seen in FIGS. 2 and 3. Regardingthe remaining elements of FIG. 1, the remaining elements are provided toapply a force to an external surface of lens element 10. Referring tothe specific embodiment of FIG. 1, there is provided a pressure element4 (a specific embodiment of which is referred to herein as a “pushring”) for contacting deformable membrane 3, and an actuator element(actuator) 20 for actuating pressure element 4. Actuator 20 in theembodiment of FIG. 1 is provided by an ion conductive electro-activepolymer (EAP). Actuator 20 in the embodiment of FIG. 1 includes a firstconductor element 6 a, a second conductor element 6 b, and a deformableelement 5 comprising a plurality of tab-like elements 5 a interposedbetween the first conductor element 6 a and second conductor element 6b. First conductor element 6 a includes an electrical contact (hiddenfrom view in FIG. 1) and second conductor element 6 b also includes anelectrical contact 6 c. The apparatus of FIG. 1, which may be termed a“focus module” or “focus apparatus” for use in focusing an image onto animage plane, can further include a housing 7 for housing the elements10, 4, and 20. Referring again to deformable element 5 of actuator 20,deformable element 5 can comprise one or more layers of conductivepolymer material such that tab-like elements 5 a bend generally in thedirection of axis 15 toward deformable lens element 10 responsively toan electrical signal being applied to conductor elements 6 a and 6 b.Assembled form side views of apparatus 100 described in FIG. 1 are shownin FIGS. 2 and 3.

For varying the optical characteristics of deformable lens element 10,voltage can be applied to the electrical contacts of first conductorelement 6 a and second conductor element 6 b to cause bending oftab-like elements 5 a. As indicated by the assembled form side views ofFIGS. 2 and 3, tab-like elements 5 a can be arranged to engage pressureelement 4 so that when tab-like elements 5 a bend toward deformablemembrane 3, pressure element 4 applies a force to an external surface ofdeformable membrane 3. As is indicated by the views of FIGS. 1-3,deformable lens element 10 can include a generally circle shaped surfaceprovided in the embodiment shown by deformable membrane 3 and caninclude an axis 15 intersecting centers of opposing lens surfaces(provided in the embodiment shown by the exterior surfaces of membrane 3and boundary element 1). Further, pressure element 4 can be ring-shapedso that pressure element 4 can apply a force generally in a directioncoextensive with axis 15 at a plurality of points spaced apart from andperipherally disposed about axis 15 of lens element 10. Apparatus 100can be adapted so that when tab-like elements 5 a curve towarddeformable membrane 3, membrane 3 bulges in a direction opposite theapplied force to define a convex lens surface, as shown in FIG. 2.

In the embodiment of FIGS. 2 and 3, apparatus 100 has two states;namely, a “power off” state in which tab-like elements 5 a bias pressureelement 4 toward membrane 3 to cause membrane 3 to bulge to define aconvex lens surface and a “power on” state depicted in FIG. 3 in whichtab-like elements 5 a pull pressure element 4 away from deformablemembrane 3 so that deformable membrane 3 is allowed to assume agenerally flat and non-convex configuration as best seen in FIG. 3. Forproviding the control depicted in FIGS. 2 and 3, electro-active polymeractuator 20 can be provided so that tab-like elements 5 a are normallybiased toward deformable membrane 3 in the absence of voltage beingapplied to the contacts of actuator 20 and are biased in a directiongenerally parallel with the plane of membrane 3 (generally perpendicularto axis 15) when in a flat configuration as best seen in FIG. 3 when acertain voltage is applied to the electrical contacts of electro-activepolymer actuator 20. In the embodiment depicted in FIGS. 2 and 3,removal of voltage from conductor elements 6 a and 6 b causes tab-likeelements 5 a to urge pressure element 4 toward membrane 3, causingmembrane 3 to bulge thereby changing an optical characteristic ofdeformable lens element 10.

Further regarding the embodiment of FIGS. 1-3, it is shown thatdeformable lens element 10 includes an axis 15 extending transverselytherethrough and that actuator 20 applies a force to a surface ofdeformable lens element 10 in a direction generally coextensive withaxis 15. In a further aspect, it is shown that pressure element 4 in theembodiment of FIGS. 1-3 will contact deformable lens element 10 at aplurality of contact positions that are spaced apart from andperipherally disposed about axis 15. Referring to the embodiment ofFIGS. 4 and 5, in the embodiment of FIGS. 4 and 5 clear boundary element1 with first and second planar surfaces 110 and 111 as shown in FIGS.2-3 is replaced with a boundary element 1 having an optical power.Boundary element 1 of the embodiment of FIG. 4 has an un-curved (planar)first surface 112 and a convex second surface 113. Boundary element 1 inthe embodiment of FIG. 5 has a concave first surface 114 and a convexsecond surface 115.

In FIGS. 1-3 a first apparatus for moving a deformable lens element 10by application of a force to an external surface of the lens element isdescribed. Alternative apparatuses wherein a force can be applied to adeformable lens element 10 to cause variation in an opticalcharacteristic (e.g., lens element surface curvature, focal length) of adeformable lens element are now herein described.

Referring now to the exploded assembly view of FIG. 6, an alternativeembodiment of focus apparatus 100 is shown and described. In theembodiment of FIG. 6, deformable lens element 10 is provided by amodular assembly described more fully herein, and actuator 20 (shown inthe embodiment of FIGS. 1-3 as being provided by an ion conductiveelectro-active polymer actuator) is provided in the embodiment of FIG. 6by a dielectric electro-active polymer actuator 20.

Referring to actuator 20 in the embodiment of FIG. 6, actuator 20 cancomprise a flexible member 21, a spring 23, a stopper 25 and flexiblecircuit board 27 for supplying voltage to flexible member 21. Referringto flexible member 21, flexible member 21 can comprise a dielectric filmmaterial interposed between flexible electrodes which can be providede.g., by conductive carbon particles suspended in a polymer matrix. Whena voltage is applied to the flexible electrodes, flexible member 21expands in the direction perpendicular to the electric field lines.Spring 23 operates to bias flexible member 21 in a direction towarddeformable lens element 10. Spring 23 shown as being provided by aconventional coil spring can substituted for by, e.g., pressurized fluidor resilient foam. Regarding stopper 25, stopper 25 operates to holdspring 23 at a certain position relative to flexible member 21 whileflex circuit 27 supplies voltage to flexible member 21 having a distalend. When power is applied to flex circuit 27, the operation of which isdescribed more fully herein, flexible member 21 expands to push flexiblemember 21 in the direction of lens element 10. More specifically, whenpower is applied to flex circuit 27, flexible member 21 pushes pressurering 4 toward deformable lens element 10. Pressure ring 4 driven byactuator 20 thereby deforms deformable lens element 10 to change anoptical property of deformable lens element 10. As in the embodiment ofFIGS. 1-3, pressure element 4, (shown as being produced in a ringconfiguration) can be adapted to contact deformable lens element 10 at aplurality of positions about a periphery of deformable lens element 10.The plurality of contact positions are defined peripherally about andspaced apart from axis 15 of deformable lens element 10. As in theembodiment of FIGS. 1-3, apparatus 100 in the embodiment of FIG. 6 isadapted so that an optical property of a deformable lens element 10 isvaried by applying a force generally in a direction of axis 15 at aplurality of contact points on deformable lens element 10 definedperipherally about axis 15.

Referring to further aspects of the focus apparatus of FIG. 6, focusapparatus 100 can be packaged with use of housing 17 sized and shaped toreceive deformable lens element 10 in the modular assembly form shown inthe embodiment of FIG. 6 and cover 18 which can be adapted to be snapfit onto bolts 19 a, 19 b, 19 c, and 19 d. Housing 17 can have aplurality of threaded holes aligned with holes of elements 21, 25, andflex circuit 27 as shown. Bolts 19 a, 19 b, 19 c, and 19 d can be driventhrough the aligned through holes and threaded into the shown threadedholes of housing 17 for assembly of apparatus 100. Focus apparatus 100can be adapted so that one or more bolts 19 a, 19 b, 19 c, and 19 dconduct electrical current between flex circuit board 27 and flexiblemember 21. For example, flex circuit board 27 and flexible member 21 canbe adapted so that bolt 19 b connects a voltage terminal of flex circuitboard 27 to a first flexible electrode of flexible member 21 and canfurther be adapted so that bolt 19 c completes a conductive path betweena second flexible electrode of flexible member 21 and flex circuit 27.

Now referring to the embodiment of FIGS. 7-9, actuator 20 in theembodiment of FIGS. 7-9 is provided by a hollow stepper motor. Referringto operation of actuator 20 of the embodiment of FIGS. 7-9 provided by ahollow stepper motor, supplying current through one or both of coil 31or coil 33 causes hollow rotor 35 threadably received on stationarybarrel 37 to rotate in such manner that by rotating rotor 35 advances ineither direction along axis 15 depending on the signals applied to coils31 and 33. In the manner as shown in the embodiment of FIGS. 1-6, rotor35 can be shaped so that an end of rotor 35 or a structure elementtransferring a force generated by rotor 35 contacts a surface ofdeformable lens element 10 at a plurality of positions peripherallydisposed about and spaced apart from axis 15 thereof. When rotor 35 inthe embodiment of FIGS. 7-9 is caused to rotate, rotor 35 whilecontacting deformable lens element 10 at such positions applies a forcein a direction generally in the direction of axis 15 to cause an opticalproperty of deformable lens element 10 to change. The force generated byactuator 20 can be transferred to lens element 10 by pressure element 4as shown in FIGS. 7-8. Pressure element 4, in the embodiment of FIGS.7-9, can have opposing pins 4 a which ride on complementarily formedelongated slots 39 formed within barrel 37 so that rotation of pressureelement 4 is resisted. Further regarding focus apparatus 100 of theembodiment of FIGS. 7-9, focus apparatus 100 can further include a cap38 threadably received on barrel 35 as shown. Cap 38 has a transparentinterior (not shown) to permit light to pass therethrough and forms astopper resisting movement of deformable lens element 10 when rotor 35is actuated to apply a force to an external surface of deformable lenselement 10.

Operation of actuator 20 in the hollow stepper motor embodiment of FIGS.7-9 is now further described. A hollow stepper motor, in one embodiment,generally is characterized by a permanent magnet equipped inner barrel,forming the rotor portion of the motor. A hollow stepper motor, in oneembodiment, can further be characterized by a coil equipped outerbarrel, supporting the inner barrel (rotor). Hollow stepper motorsexhibit reduced size relative to other types of motors and allow forprecision adjustment of lens element positions. In one embodiment, aninner barrel portion of a hollow stepper motor can include threads thatare threadably received in threads of an outer barrel. With such athread arrangement, the motor can sustain high impact relative to gearbased motor arrangements. In one embodiment, threads for receiving aninner barrel in relation to an outer barrel can include threadscomplementarily configured so that an inner barrel is maintained at aposition with respect to outer barrel 37 by way of frictional forces andwithout application of external energy. Accordingly, a lens setting canbe controlled to remain at a certain setting simply by avoidingsupplying current to a lens driver coil. By comparison, alternativeactuators, while desirable in some instances, require applied power formaintaining a fixed lens setting. Accordingly, a major advantage of ahollow stepper motor, in one embodiment is reduced power consumption.

Regarding outer barrel 37, outer barrel 37 can comprise a set of coils32 corresponding to inner barrel 35. A set of coils 32 includes firstcoil 31 and second coil 33.

Further, outer barrel 37 includes teeth 41 for engaging teeth 43 ofinner barrel 35. The combination of teeth 41 and teeth 43 providemovement of inner barrel 35 along axis 15 when inner barrel 35 is causedto rotate.

Operation of an exemplary hollow stepper motor is further described withreference to FIG. 9. Inner barrel 35 can have permanent magnets 45 ofalternating north and south polarity, which are alternately formed aboutthe circumference of inner barrel 35. First coil 31 can have alternatingteeth 47, 49 defined by gap 51. When current flows through coil 31 in aforward direction, magnetic fields of opposite polarity are formed atsuccessively adjacent teeth, e.g., teeth 47, 49 of coil 31. When currentflows through coil 31 in a backward direction, magnetic fields ofopposite polarity are again formed at successively adjacent teeth ofcoil 31, except the polarity of the magnetic field is the opposite ofits polarity during forward direction current flow. Similarly, secondcoil 33 can have alternating teeth 55, 57 defined by gap 59. Whencurrent flows through coil 33 in a forward direction, magnetic fields ofopposite polarity are formed at successively adjacent teeth. Whencurrent flows through coil 33 in a backward direction, magnetic fieldsof opposite polarity are again formed at successively adjacent teeth ofcoil 33, except the polarity of the magnetic field is the opposite ofits polarity during forward direction current flow.

For rotating inner barrel 35, current can be applied in forward andbackward direction in first and second coil 31, 33 in a timed sequencecoordinated manner to urge inner barrel 35 in a desired direction untila desired position of barrel 35 is achieved. When teeth of coil 31 orcoil 33 have a certain polarity, it is seen that inner barrel 35 willhave a certain position relative to outer barrel 37 such that permanentmagnets thereof are aligned with teeth of coil 31 or coil 33. Thus,using the actuator 20 of FIGS. 7-9, precise positioning of lens elementscan be achieved. The motor described with reference to FIGS. 7-9 isreferred to as a hollow stepper motor since discrete stepwise positionsof inner barrel 35 relative to outer barrel 37 can be achieved whereinpermanent magnets of the barrel are aligned with coil teeth having acertain polarity.

With the end of inner barrel 35 being generally ring-shaped in themanner of pressure element 4, actuator 20, as shown in the embodiment ofFIGS. 7-9 can operate substantially in the manner of the embodiment ofFIGS. 1-3, and of FIG. 6. That is, actuator 20 as shown in FIGS. 7-9 canapply a force generally in the direction of axis 15. For application ofthe force, deformable lens element 10 as shown in FIG. 5 can becontacted at a plurality of contact positions defined on an exteriorsurface of deformable lens element 10 at a plurality of points spacedapart from axis 15 and peripherally disposed about axis 15.

Specific examples of various constructions of deformable lens element 10which can be interchanged into any one of the embodiments of focusapparatus 100 described are described herein in connection with FIGS.10-17.

In the embodiment of FIG. 10, deformable lens element 10 comprises firstclamping element 63 second clamping element 65 and deformable membrane 3interposed between first clamping element 63 and second clamping element65. Each of the first and second clamping elements 63 and 65 can betransparent (optically clear) and disk shaped as shown and can includerespective annularly disposed interlocking teeth. Specifically in theembodiment shown, clamping element 63 includes three annularly formedtooth rings 64 and clamping element 65 includes a pair of annularlydisposed tooth rings 66 as best seen in FIGS. 11-12 that engage theteeth of the clamping element 63. While in the embodiment shown aplurality of annular rings are provided on each of clamping element 63and clamping element 65 it is seen that a holding force between clampingelement 63 and clamping element 65 would be aided by the presence of afewer number of tooth rings, e.g., only a single annular tooth ring onone of the clamping elements. In such manner membrane 3 is clampedbetween clamping element 63 and clamping element 65.

For assembly of the deformable lens element of FIGS. 10-12, clampingelement 65 can be press fit onto clamping element 63 and then can beultrasonically welded thereto. In another aspect clamping element 63 andclamping element 65 can have complementary tongue and groove engagingsurfaces at which an ultrasonic weld can be formed. In the embodiment ofFIGS. 10-12, clamping element 63 includes an annular groove 71 (FIGS.10-12) and clamping element 65 includes an annular tongue 73 (FIGS.10-12). However, in an alternative embodiment, the location of thetongue and groove can be reversed. The ultrasonic weld at the interfacebetween tongue and groove can be supplemented or replaced e.g., with anadhesive suitable for use with the material of the clamping elements.Planar optically clear window 67, as shown in the embodiment of FIG. 11,can be replaced with a curved surfaced member having an optical power.An alternative window for use with the deformable lens element as shownin FIGS. 10-12 can have, e.g., the curved surfaces of element 1, asshown in FIG. 4 (surfaces 112 and 113) and FIG. 5 (surfaces 114 and 115)herein.

In another aspect, clamping element 63 can have a transparent wall 67allowing light to pass therethrough and can have a sufficient thicknessto define a cavity 8 for receiving focus fluid or another deformablesubstance. After clamping element 63 and clamping element 65 areultrasonically welded, focus fluid having an index of refraction greaterthan 1 (where the lens element incorporates a focus fluid) can be inputinto cavity 8 through hole 75. After the cavity is filled, the hole 75can be sealed. Regarding clamping element 63 and clamping element 65each of clamping element 63 and clamping element 65 can be formed ofsolid non-deformable material. Further, clamping element 65 can definean aperture 77 to allow a force supplying element (e.g., pressureelement 4 or actuator 20 if pressure element 4 is deleted) to contactmembrane 3.

Another embodiment of deformable lens element 10 is shown and describedin FIG. 13. In the embodiment of FIG. 13, deformable lens element 10 hasa pair of deformable lens surfaces; namely, a first surface defined byfirst deformable membrane 3 and a second surface defined by seconddeformable membrane 3′. Deformable lens element 10 in the embodiment ofFIG. 13 is constructed in the manner of the deformable lens element 10of FIGS. 10-12 except that clamping element 63 holding deformablemembrane 3 is repeated and clamping element 63 is modified for receiptof second membrane 3′ and a second clamping element 65 on an oppositeside thereon. In the embodiment of FIG. 13, it is seen that deformablelens element 10 has teeth as described in connection with the embodimentof FIGS. 10-12 for securely holding membranes and annular tongue andgroove fasteners formed therein for securely holding a clamping elementin relation to clamping element. Regarding window 67′ of center clampingelement 63′, and where the lens element 10 incorporates a focus fluid,the window 67′ can be formed so that a first and second fluid tightcavity for holding focus fluid are defined in the deformable lenselement 10 of FIG. 13. Alternatively, the first and second cavities canbe in fluid communication e.g., by way of through holes formed in awindow 67′. Also, window 67′ can be deleted and the cavities can be influid communication through an aperture defined by the inner mostannular tooth ring of center clamping element 63′.

Regarding FIG. 14, FIG. 14 shows an embodiment of a focus apparatus 100incorporating the deformable lens element 10 shown in FIG. 13 whereinboth of a light entry and light exit surface of the lens element 10 aredeformable. Regarding the embodiment of FIG. 14, focus apparatus 100 canhave a pair of actuators 20 disposed on either side of deformable lenselement 10 including deformable membrane 3 and deformable membrane 3′. Afirst actuator 20 can be disposed as shown to impart a force on anexterior surface of first membrane 3 which may define a light entrysurface of deformable lens element 10 and a second actuator 20 can bedisposed as shown to impart a force on an exterior surface of secondmembrane 3′ which may define a light exit surface of lens element 10. Inthe embodiment of FIG. 14, both of the first and second actuators canhave the characteristics described with reference to the embodiment ofFIGS. 1-3. For example, both of the actuators 20 can be disposed so thatan aperture 16 of the actuator 20 is disposed about an axis 15 ofdeformable lens element 10. Each of the actuators 20 can be furtherarranged so that a force generated by the actuator 20 is imparted to thelens element 10 in a direction generally coextensive with axis 15 andfurther so that the deformable surface of the deformable lens element 10is in contact at a plurality of contact positions spaced apart from andperipherally disposed about axis 15. In one embodiment of an opticalsystem incorporating the lens element 10 of FIG. 13, membrane 3 can forma light entry surface of the lens element and membrane 3′ can form alight exit surface. In another embodiment, lens membrane 3′ forms alight entry surface of the lens element and membrane 3 forms a lightexit surface.

Further regarding the focus apparatus 100, it is seen that the first andsecond actuators 20 have apertures 16 disposed about, and in oneembodiment, substantially centered on axis 15 of deformable lens element10 in such manner that a first of the actuators imparts a force in adirection generally coextensive with the axis 15 on a light entrydeformable lens surface of the lens element while a second of theactuators 20 imparts a force in a general direction of axis 15 on alight exit surface of the deformable lens element 10.

It is seen that the deformable lens element 10 of FIG. 13 arranged withappropriate actuators as shown in FIG. 14 can be controlled to exhibit avariety of major lens element configurations, e.g., planar convex,planar concave, bi-convex, biconcave, concave-convex, meniscus,bi-convex with non-equal surface power.

Regarding deformable membrane 3 and membrane 3′ in the variousembodiments of deformable lens element 10, the deformable membranes cancomprise nonporous optically clear elastomer material. A suitablematerial for use as membrane 3, 3′ is SYLGARD 184 Silicon elastomer, ofthe type available from DOW CORNING.

Regarding cavities 8 described in the various embodiments, cavities 8can be filled with optically clear focus fluid. Selecting a focus fluidwith a relatively high index of refraction will reduce the amount ofdeformation needed to obtain a given change in focal distance. In oneexample, a suitable index of refraction would be in the range of fromabout 1.3 to about 1.7. Selecting a focus fluid with a smaller index ofrefraction is advantageous where it is desired to increase the amount ofdeformation needed to obtain a given change in focal distance. Forexample, in some embodiments where a selected actuator 20 generatesrelatively coarse movements, a focus fluid having a lower index ofrefraction might be selected. One example of a suitable focus fluid(optical fluid) is SL-5267 OPTICAL FLUID, available from SANTOLIGHT,refractive index=1.67.

Further regarding cavities 8 of the various embodiments, the cavitiescan be filled with an alternative deformable optically clear substancehaving an index of refraction greater than 1 that does not, in themanner of a fluid, assume the shape of its respective cavity 8 when ofgreater volume than the substance. For example, a deformable shaperetaining material which can substantially retain its unstressed shapethroughout its lifetime can be disposed in cavity 8 in each of thevarious embodiments of deformable lens element 10.

In one example, a silicon gel can be provided as a resilientlydeformable shape retaining material that substantially retains itsunstressed shape over the course of its lifetime. A resilientlydeformable silicon gel can be disposed in cavity 8 of any of thedescribed embodiments. For manufacture of a suitable silicon gel for usewith a deformable lens element 10 described herein, liquid silicon canbe filled into a container of the desired shape of completed gel memberand then cured. In one example, the liquid silicon can be filled into amold in the shape of cavity 8 into which the silicon gel member will bedisposed, and then cured until in silicon gel form.

Further, with reference to manufacture of a resiliently deformablemember, a mold core can be prepared with aluminum by single pointdiamond turning and nickel plating. The cavities can have the negativeshape of the resiliently deformable lens element to be made. Next, asilicon gel mixture can be prepared such as DOW CORNING JCR6115 two partsilicon Heat Cure gel. The two parts, JCR6115 CLEAR A and JCR6115 CLEARB are mixed to form a mixture. The mixture can be vacuumed to releasebubbles formed therein. With the liquid silicon gel prepared, the liquidsilicon gel can be injection molded into the mold core. The liquidsilicon gel can then be cured under an elevated temperature. WhereJCR6115 liquid silicon available from DOW CORNING is used, the liquidgel can be cured by heating for 5 minutes at 175 degrees. The completedsilicon gel lens can then be inspected to determine whether it is freeof defects and extra material can be removed around the gate area.Optionally, the finished resiliently deformable member can be spincoated with a thin membrane material e.g., SYLGARD 184 from DOW CORNINGto improve durability. Several materials that can be utilized in theform of a resiliently deformable member for as in a deformable lenselement or component thereof are summarized in Table A below. In each ofthe exemplary embodiments, the material constituting a major body of adeformable lens element (including some instances the entire resilientlydeformable lens element) has a hardness measurement of less than Shore A60.

TABLE A Example Material and Sample Characteristics 1 Dow Corning,JCR6115, Two Part, Fast Heat Cure, Low Modules Gel With Low ViscosityAnd Very Long Working Time. Cure 5 minutes @ 175° C., Refractive Index1.404, Young's Modulus 0.2 Mpa, Operation Temperature −45°-200° C.,Elongation 130%, Hardness, Shore A 13 2 Opti-tec, Optically ClearSilicon Rubber. Cure 1 hour @ 100° C., Refractive Index 1.406, OperationTemperature −60°-200° C., Elongation 100%, Hardness, Shore A 40 3Rogers, BISCO HT-6240 Liquid Silicon Rubber Sheet. Optical: Clear,Operation Temperature −80°-425° C., Elongation 250%, Hardness, Shore A40 4 Dow Corning, SYLGARD ® 184 SILICONE ELASTOMER. Cure 10 minutes @150° C., Refractive Index 1.430, Young's Modulus 2.0 MPa, OperationTemperature −45°-200° C., Elongation 140%, Hardness, Shore A 50

In each of the exemplary embodiments, the material forming a resilientlydeformable member is provided by an optically clear silicon gelelastomer having an index of refraction greater than 1. However, it willbe understood that any optically clear resiliently deformable materialhaving an index of refraction greater than 1 can be utilized in themanufacture of a deformable lens element.

When in a silicon gel form the formed silicon gel member can be disposedin cavity 8. It will be seen that whereas filling focus fluid andsealing can normally be last steps in a lens element manufacturingmethod where a lens element incorporates a fluid, disposing a gel memberin a cavity can normally be an intermediate step in the manufacture of agel based deformable lens element.

Referring to FIG. 15, another embodiment of deformable lens element 10is illustrated. The embodiment of FIG. 15 has a construction similar tothat of the embodiment of FIGS. 10-12 with resiliently deformable lensmember 80 disposed (e.g., comprising silicon gel) in a cavity delimitedby clamping member 63 and clamping member 65 in place of focus fluid.Further regarding the embodiment of FIG. 15, pressure element 4 providedby a push ring is mechanically coupled to clamping member 65 forpurposes of aiding the alignment of pressure element 4 with deformablemembrane 3.

Where a deformable lens element incorporates a deformable shaperetaining material such as can be provided by silicon gel, features ofdeformable lens element 10 for sealing of cavity 8 can be optionallydeleted. In the embodiment of FIG. 16, cavity 8 is deleted anddeformable lens element 10 comprises a stacked layer constructionincluding resiliently deformable material member 80, deformable membrane3, back plate 81 and forward plate 82 adapted to mechanically couplepressure element 4 as shown.

Where deformable lens element 10 incorporates a shape retainingresiliently deformable member such as a deformable member comprisingsilicon gel as described herein, deformable membrane 3 can be optionallydeleted. Nevertheless, with membrane 3, resiliently deformable member 80may be advantageously protected and the incidence of scratches on thesurface of resiliently deformable member 80 can be reduced. Additionallyor alternatively for protecting resiliently deformable member 80, member80 may be subject to a coating processing wherein optically clearprotective coating 84, such as may comprise SYLGARD 184 from DOW CORNINGcan be applied to gel member 80 as has been described herein. An exampleof a deformable lens element 10 comprising a resiliently deformablemember 80 and a surface protective coating 84 is shown in FIG. 17.

It has been mentioned that a process for manufacture of a shaperetaining resiliently deformable optically clear member can includefilling a container of a desired shape of the finished member and thencuring. In one embodiment, a shape retaining resiliently deformablemember, as described herein can be formed to have an initial opticalpower. In one embodiment, a shape retaining resiliently deformablemember can be formed so that in an unstressed state the deformablemember has at least one convex lens surface.

In the embodiment of a focus apparatus 100 as shown in FIG. 18,resiliently deformable member 80 can be formed to have an initialoptical power, and is specially configured so that in an unstressedstate resiliently deformable member 80 has a first normally (unstressedstate) convex surface 85 and a second normally (unstressed state) convexsurface 86. One of the lens surfaces 85 or 86 can be regarding as alight entry surface and the other a light exit surface. Furtherrespecting the focus apparatus 100 of FIG. 18, first and secondelectro-active polymer actuators 20 can be disposed to deform each ofthe first and second normally convex surfaces. In one embodiment of FIG.18, lens element 10 is shown as being provided as a one piece memberconsisting of resiliently deformable member 80. In the embodiment ofFIG. 18, as well as in the remaining embodiments described wherein amajor body of the deformable lens element 10 comprises a resilientlydeformable material member, deformable lens element 10 can be devoid ofa focus fluid.

In the exemplary embodiment of FIG. 18, actuators 20 for deformingdeformable lens element 10 can comprise dielectric electro-activepolymer flexible members 21 as described previously in connection withthe embodiment of FIG. 6. In the embodiment as shown in FIGS. 18-19,flexible members 21 are normally biased outward by resilientlydeformable member 80 and hence spring 23 is not included in theembodiment of FIGS. 18 and 19. Also, pressure element 4 is deleted inthe embodiment of FIGS. 18 and 19 and the force imparting structuralelement in the embodiment of FIG. 18 and FIG. 19 is provided by actuator20. Each flexible member 21 can be disposed to contact deformable lenselement 10 provided in the embodiment of FIGS. 18 and 19 by a one pieceresiliently deformable member which in one embodiment comprises asilicon gel. Specifically with reference to the embodiment of FIGS. 18and 19, each flexible member 21 can be adapted to substantially conformto the unstressed shape of a deformable lens element provided in theembodiment shown by a one piece resiliently deformable member 80. As inthe embodiment of FIG. 18, each flexible member 21 can includedielectric film material layer 90 interposed between a pair of flexibleelectrode layers 91 and 92 such that by varying the voltage between theflexible electrode layers, the flexible member expands or contracts. Inanother embodiment the single dielectric layer 90 can be replaced bymultiple dielectric layers. Further referring to the focusing apparatus100 of FIG. 18, each flexible member 21 can include an uncoated area 116disposed about lens element axis 15 to allow light rays to pass throughdeformable lens element 10.

Uncoated areas 116 in the embodiment of FIG. 18 are areas devoid offlexible electrode coating which coating can cover the remainder of theinternal and external surfaces of flexible member 21 in areas other thanthe uncoated areas 116. For providing dielectric layer 90 in anoptically clear form for permitting light to pass there through,dielectric layer 90 can comprise a suitable optically clear material,examples of which include Acrylic, model number VHB4910, available from3M, and model number CF19-2186 Silicon available from NUSIL. Formanufacture of a flexible member 21 as shown in the embodiment of FIG.18, an optically clear muscle dielectric material can be spin cured on acarrier substrate (glass plate) to form a uniform thin film. The filmcan then be cured at an elevated temperature. After curing, the film canbe detached from the substrate and electro-chemically coated to form aflexible electrical coating except in uncoated areas 116. The formedflexible member can be cut to appropriate size and mounted. In a furtheraspect, when voltage is applied to contract a flexible member 21, theresulting force initially generated in a direction generallyperpendicular to axis 15 is imparted to deformable lens element 10generally in the direction of axis 15 toward lens element 10 in suchmanner that the convexity of lens element is increased. With apertures16 ring-shaped and disposed about axis 15 and with flexible member 21adapted to substantially conform to the shape of deformable lenselement, a contraction of a flexible member 21 results in forcesgenerally in the direction of axis 15 toward deformable lens elementbeing imparted at a plurality points peripherally disposed about andspaced apart from axis 15. While the force imparted to lens element 10by actuators 20 in the embodiment of FIG. 18 can be described as beinggenerally in the direction of lens element axis 15, it is understoodthat if the forces imparted are broken down into normal (axis directed)and transverse (perpendicular to axis 15) constituent component forcevectors in the embodiment of FIG. 18 can be expected to have a higherpercentage of transverse component force vectors than in the embodimentsdescribed herein with reference to FIGS. 1-9.

Further regarding focus apparatus 100 as described in FIG. 18, voltageterminals can be provided in such manner as to appropriately supplyvoltages across the flexible electrode layers 91 and 92 of therespective first and second flexible members 21 shown. Voltage terminalsas will be described in an exemplary embodiment can also be provided tostructurally support flexible members 21 in a certain position inrelation to lens element 10 and the flexible members 21 in turn supportresiliently deformable lens element 10. In the embodiment shown in FIG.18, imaginary lines connecting terminal connecting interfaces 125 andinterfaces 127 (where a first flexible member 21 is connected toconductive rings 94 and 98 and a second flexible member is connected toconductive rings 98 and 96) can bisect deformable lens element 10. Insuch manner the flexible member 21 in the embodiment shown can impart aforce generally in the direction of axis 15 toward lens element 10 whencontrolled to move to a contracted state.

The components of the embodiment of FIG. 18 are further described withreference to FIG. 19 showing an exploded assembly view of the embodimentin accordance with FIG. 18. Referring to the view of FIG. 19, it isfurther seen that focus apparatus 100 includes bi-convex resilient(shape-retaining) deformable lens element 10 provided by one piecedeformable member 80 interposed between a pair of flexible members 21 offirst and second actuators 20 adapted to substantially conform to theshape of deformable lens element 10 when in an unstressed state.Referring to further aspects of focus apparatus 100 as shown in FIG. 19,focus apparatus 100 can further include housing elements 93, conductiverings 96 and 94, insulating sleeve 97, and center conductive rings 98.Conductive ring 94, center ring 98, and conductive ring 96 are fittedinside insulating sleeve 97, which is disposed to prevent a shortbetween housing element 93 and conductive ring 94 and between housingelement 93 and center conductive ring 98. In a further aspect,conductive ring 96 can be in conductive contact with conductive housingelement 93. For actuating of first and second actuators 20 having firstand second flexible members 21, a voltage can be applied across housing93 (in conductive contact with conductive ring 96) and conductive ring94. In the embodiment shown, center conductive ring 98 operates as anode in a series circuit that comprises the respective dielectric layersof a first flexible member 21 and second flexible member 21, wherein thenode connects the noted elements. Application of a voltage acrosshousing 93 (and therefore ring 96) and ring 94 can cause the first(disposed between ring 94 and ring 98) and second (disposed between ring96 and ring 98) flexible members 21 to be actuated simultaneously. Inanother embodiment center conductive ring 98 can be in electricalcommunication with a reference voltage and voltages can be appliedbetween the conductive ring 96 and ring 98 and also between ring 94 andring 98 for independent control of the first and second flexible members21 of the first and second actuators 20. The various elements of FIGS.18 and 19 can be sized to be frictionally fit so that the elements arein certain relative position when apparatus 100 is fully assembled.

In another embodiment, the dielectric electro-active polymer actuator asshown in FIGS. 18-19 can be replaced by an ion conductive electro-activepolymer actuator, as described previously herein. An ion conductivepolymer actuator can have the configuration of the actuator as depictedin FIGS. 18-19, except that optically clear dielectric layer 90 can bereplaced with one or more optically ion conductive polymer layers.

Where the actuator 20 as shown in FIGS. 18-19 represents a dielectricelectro-active polymer actuator the actuator can generate force (bycontraction of the actuator) in a direction generally perpendicular toaxis 15, which force is imparted to a deformable surface of lens element10 in a direction that is generally in the direction of axis 15. Whereactuator 20 in the embodiment of FIGS. 18-19 represents an ionconductive polymer actuator, the actuator can generate a force in adirection generally in the direction of axis 15 (by bending of the ionconductive layer) which force is imparted to a deformable surface oflens element generally in the direction of axis 15. The voltagerequirements of focus apparatus 100 can be reduced (e.g., to less that10 volts) with selection of an ion conductive electro-active polymeractuator.

In the embodiments having an electro-active polymer actuator 20 with anuncoated area region 116 (e.g., either of the dielectric type or an ionconductive type), the uncoated area 116 can be replaced with an aperture16 so that the actuator 20 operates in the manner of a force impartingstructural element having an aperture 16 as described herein.

Also embodiments herein having force imparting elements including anaperture, the aperture 16 can be filled with an optically clear materialmember so that the force imparting structural element operates in themanner of the actuator of FIGS. 18-19. As has been described herein, theactuator in any of the described embodiments can be substituted for byan actuator of any of the remaining embodiments. Likewise the deformablelens element in any of the described embodiments can be substituted forby a deformable lens element of any of the remaining embodiments.

While the embodiments of FIGS. 18 and 19 include a deformable bi-convexlens element and an actuator for deforming each of a pair of lenssurfaces, it is seen that focus apparatus 100 could alternativelycomprise a piano-convex resiliently deformable shape-retaining lenselement and a single actuator for deforming the normally convex lenssurface.

In any of the described embodiments wherein a force generated byactuator 20 is transferred to deformable lens element 10 by pressureelement 4, it is understood that pressure element 4 can be deleted andthat a force generated by actuator 20 can be imparted on deformable lenselement 10 directly by actuator 20. For imparting a force on deformablelens element 10, it has been described that a structural element; namelypressure element 4 or actuator 20 (if the focus apparatus is devoid ofpressure element 4), can “contact” a deformable lens element at aplurality of contact positions, or otherwise impart a force to adeformable lens element at a plurality of force impartation points.

In one embodiment of a “contacting” relationship between a structuralelement and deformable lens element as described herein, theforce-applying structural element can be in separable contact with thedeformable lens element, meaning that the force supplying the structuralelement can be freely separated from the deformable lens element. Inanother embodiment of a “contacting” relationship described herein, theforce-applying structural element can be in secure contact with thedeformable lens element, meaning that it is adhered to, welded to,biased toward, or otherwise connected to the deformable lens element.

In another embodiment, the force-applying structural element, (e.g., theactuator or pressure element) is integrally formed with the deformablelens element, meaning that the force applying structural element is partof a one piece member, a part of which forms the force applyingstructural element, and a part of which forms at least a part ofdeformable lens element 10.

Where the force applying structural element is in secure contactingrelationship with a deformable surface of the deformable lens element oris integrally formed with the deformable surface, a pulling forcegenerated by actuator 20 (i.e., in the direction of axis 15 but awayfrom deformable lens element 10) can operate to deform the deformablelens element. A pulling force imparted on a surface of a deformable lenselement imparted at a plurality of points peripherally disposed aboutand spaced apart from axis 15 can be expected to decrease a convexity orincrease a concavity of the deformable surface where the force applyingstructural element is ring shaped. Where a force applying structuralelement (member) is ring shaped as described herein, the force applyingstructural element can impart a force to a deformable lens element at aplurality of points spaced apart from and peripherally disposed aboutaxis 15 of lens element 10. The force applying structural element canimpart a force at a plurality of points spaced apart from andperipherally disposed about axis 15 whether the force applying elementis in separable contacting, secure contacting, or whether the forceapplying structural elements is integrally formed with the deformablelens element. Force can be imparted to a deformable surface of adeformable lens element at a plurality of force impartation pointshaving characteristics that vary depending on the shape of the forceimparting structural element. Where the force imparting element is ringshaped, a plurality of force impartation points can be formed in a ringpattern about axis 15. Ring shaped force imparting elements as describedherein have been shown as being circular; however, ring shaped forceapplying elements can also be oval, asymmetrically arcuate, orpolygonal. Where a force imparting element is ring shaped, forceimparting points of a deformable surface, at least a part of whichtransmits image forming light rays, do not include points within a twodimensional area about axis 15 delimited by the plurality of forceimparting points in a ring pattern peripherally disposed about axis 15.

In the embodiment of FIGS. 18 and 19, an actuator can impart a force todeformable surface of a deformable lens element generally in thedirection of axis 15; however, in the embodiment of FIGS. 18 and 19, theforce impartation points are not formed in a ring pattern that excludespoints within a two dimensional area about axis 15. In the embodiment ofFIGS. 18 and 19, force impartation points include points within a twodimensional area about axis 15 of a deformable surface at least part ofwhich transmits image forming light rays. In one embodiment, the forceimpartation points can be points of a surface of deformable lens element10 facing an exterior of deformable lens element 10. Force impartationpoints in various examples are depicted in FIGS. 20 and 21, wherein FIG.20 shows an exemplary view of force impartation points being defined ina ring pattern 202 at a plurality of points peripherally disposed aboutand spaced apart from axis 15, and FIG. 21 shows an exemplary depictionof force impartation points defined in an area pattern 204, whereinforce impartation points include points defining a two dimensional areaabout axis 15. Characteristics of exemplary force impartation profilesare described further in connection with Table B. Where a forceimparting element is ring shaped, a pushing force imparted to adeformable surface of deformable lens element 10 in a direction of theelement 10 can increase a convexity of the surface by encouraging thesurface to bulge outwardly along an axis and decrease in thickness alonga plurality of imaginary lines that run parallel to the axis, and whichare spaced apart from and peripherally disposed about axis 15. Where anarea force imparting element e.g., as shown in the embodiment of FIGS.18 and 19, is utilized, imparting a pushing force in the direction ofdeformable lens element 10, and the deformable element is normallyconvex, the imparted force results in flattening, or a reduction of theconvexity of the surface. Further characteristics of embodiments havingthe described exemplary force impartation profiles are summarized inTable B.

TABLE B Result of “Pulling” Force (where force imparting Force ExemplaryForce Result of structural element is adhered Impartation ExemplaryDirection of Impartation “Pushing” to or integrally formed with ProfilesEmbodiment Force Points Force a deformable surface) Ring FIGS. 1-9,Generally Defined at a A bulge can Convexity can be reduced Shaped, 14along axis 15 plurality of be formed at and if a pulling force is spacedapart positions the center sufficient, a concave lens from and forming aareas element surface can be peripherally ring pattern defined by formeddisposed at a plurality the ring about axis of positions pattern to 15peripherally increase a disposed and convexity of spaced apart the fromaxis 15 deformable lens element surface about axis 15. Area, FIGS. 18-19Generally Defined at a Deformable Thickness of deformable disposed alongaxis. plurality of lens element surface can increase along about axisWhere positions “flattens” to axis 15, to increase a 15 actuator is anforming an decrease convexity of the deformable dielectric area patternconvexity, lens surface in an area about EAP disposed or otherwise axis15. actuator, about axis reduces a force vectors 15 thickness of willinclude the a greater deformable percentage lens element of along axistransverse- 15 to-axis component vectors than in an embodiment where aforce imparting structural element is provided by a push ring.

In the embodiment of FIGS. 1-19, focus apparatus 100 can be adapted sothat an infinitesimal change in the position of actuator 20 provides asignificant change in the focus position of an optical imaging system inwhich apparatus 100 is incorporated. Specific performancecharacteristics that can be realized with use of focus apparatus 100 asdescribed herein are described with reference to the following example.

It will be seen from the embodiments of FIGS. 1-19 that the actuator andlens elements can be interchanged in any combination among theembodiments.

EXAMPLE 1

A focus apparatus for use in focusing having a structure substantiallyaccording to that shown in FIG. 6 is constructed and fitted onto a lenstriplet imaging lens assembly of an IT5000 Image Engine of the typeavailable from Hand Held Products, Inc. having a focal length of 5.88mm, an F# of 6.6 and a nominal fixed best focus distance of 36 inches.An actuator from ARTIFICIAL MUSCLE INCORPORATED (“AMI”) based on thedesign of an MLP-95 or MSP-95 auto-focus muscle actuator available fromAMI, Inc. was used. After the focus element was constructed, variousvoltages were applied to the actuator's flexible electrodes. The resultsare summarized in Table C below:

TABLE C DISTANCE MOVEMENT OF ACTUATOR (20) VOLTAGE AND PRESSURE BESTFOCUS (volts) ELEMENT (4) DISTANCE 0 0 36″  600 0.025 mm 8″ 790 0.050 mm6″ 896 0.075 mm 3″

It was observed that large variations in the best focus distance couldbe realized with infinitesimal movement of an actuator applying a forceto a deformable lens element.

[End of Example 1]

Various arrangements of the described deformable lens element in variousimaging systems are now described.

Apparatus 100 comprising deformable lens element 10 moveable by way offorce applied to an external surface thereof can be incorporated in anoptical imaging system (which may alternatively be termed a lensassembly) comprising apparatus 100 and one or more additional lenselements arranged in a series with the apparatus. The one or moreadditional lens elements can comprise deformable or non-deformable lenselements. When apparatus 100 is arranged in series with a far focusedimaging lens assembly (not shown) focused at infinity, the state (lenswithout curvature or planar) depicted e.g., in FIG. 3 will achieve a farfocus and the state depicted in FIG. 2 (convex lens) will achieve a nearfocus.

In the embodiment of FIG. 22, lens assembly 500 (which can also bereferred to as an “optical imaging system”) for transmission of imageforming light rays comprises a single deformable lens element 10disposed in a focus apparatus 100 according to any one of theembodiments discussed herein. For increasing an optical power of animaging lens assembly comprising a single deformable lens element, thelens element can be provided in a form capable of double convexconfiguration. In the embodiment of FIG. 23, imaging system 500, fortransmission of image forming light rays, comprises a single deformablelens element 10 disposed in a focus apparatus 100 according to any oneof the embodiments discussed herein in combination with subassembly 502.More specifically, focus apparatus 100 as shown in FIG. 23 is disposedin series with a lens subassembly 502 comprising one or more (asindicated by the dashed in element) rigid non-deformable lens elements11. Regarding lens assembly 500 as shown in FIG. 23, focus apparatus 100can be an add-on unit detachably received on lens subassembly 502. Inthe embodiment of FIG. 24, lens assembly 500 comprises a plurality ofdeformable lens elements 10 disposed in a modified focus apparatus 100′modified to include actuators for actuating a plurality of deformablelens elements 10. Lens assembly 500 in the embodiment of FIG. 24 furthercomprises a plurality of rigid non-deformable lens elements 11. Lensassembly 500 in each of the embodiments of FIGS. 22, 23, and 24 isdisposed in association with an object plane 540, and an image plane 550partially defined by image sensor 1032. Image sensor 1032 can beshielded from stray light rays by shroud 560, which can be integrallyformed with a housing of lens assembly 500. Where lens assembly 500includes more than a single deformable lens element 10, such additionallens elements can be aligned such that the axes of such additionalelements are coincident with axis 15. Accordingly, where lens assembly500 includes a plurality of lens elements, axis 15 can, as shown inFIGS. 23 and 24, be regarded as an optical or imaging axis of lensassembly 500.

Turning now to FIG. 25, a block diagram of an illustrative imagingterminal 1000 incorporating a lens assembly 500 as described herein isshown and described. Lens assembly 500 can be incorporated in an imagingterminal 1000.

An electrical component circuit diagram supporting operations of imagingterminal 1000 is shown in FIG. 25. Image sensor 1032 can be provided onan integrated circuit having an image sensor pixel array 1033 (imagesensor array), column circuitry 1034, row circuitry 1035, a gain block1036, an analog-to-digital converter (ADC) 1037, and a timing andcontrol block 1038. Image sensor array 1033 can be a two dimensionalimage sensor array having a plurality of light sensitive pixels formedin a plurality of rows and columns. Each sensor element of the imagesensor array 1033 can convert light into a voltage signal proportionalto the brightness. The analog voltage signal can then be transmitted tothe ADC 1037 which can translate the fluctuations of the voltage signalinto a digital form. The digital output of the ADC 1037 can betransmitted to a digital signal processor (DSP) 1070 which can convertthe image into an uncompressed RGB image file and/or a standard orproprietary image format before sending it to memory. Terminal 1000 canfurther include a processor 1060, an illumination control circuit 1062,a lens assembly control circuit 1064, an imaging lens assembly 500, adirect memory access (DMA) unit (not shown), a volatile system memory1080 (e.g., a RAM), a nonvolatile system memory 1082 (e.g., EPROM), astorage memory 1084, a wireline input/output interface 1090 (e.g.,Ethernet), short range RF transceiver interface 1092 (e.g., IEEE802.11), and a long range radio transceiver interface 1093 (e.g., GPRS,CDMA) for use in e.g., providing cellular telephone data communications.Regarding illumination control circuit 1062, illumination controlcircuit 1062 can receive illumination control signals from processor1060 and can responsively deliver power to one or more illuminationlight sources such as illumination light sources 604, and one or moreaiming light sources such as aiming light sources 610. Terminal 1000 canbe adapted so that light from light sources 604, 610 is projected onto asubstrate within a field of view of terminal 1000. Terminal 1000 canalso include a keyboard 1094, a trigger button 1095, and a pointercontroller 1096 for input of data and for initiation of various controlsand a display 1097 for output of information to an operator. Terminal1000 can also include a system bus 1098 for providing communicationbetween processor 1060 and various components of terminal 1000.

In one embodiment, imaging terminal 1000 can have software and hardwareenabling terminal 1000 to operate as a mobile telephone. For example,the terminal 1000 can include a microphone 1077 and speaker 1078 incommunication with processor 1060 over system bus 1098. Terminal 1000can also have connected to system bus 1098 long range radio transceiverinterface 1093 enabling transmittal and receipt of voice packets over acellular data communication network.

DSP 1079 can encode an analog audio signal received from microphone 1077to a digital audio signal to be transmitted to processor 1060. DSP 1079can also decode an analog audio signal to be transmitted to speaker 1078from a digital audio signal received from processor 1060. In oneembodiment, all the essential functions of the audio signal encoding anddecoding can be carried on by DSP 1079. In another embodiment, at leastsome of the audio encoding/decoding functions can be performed by asoftware program running on processor 1060.

Imaging terminal 1000 can also be adapted to operate as a video camera.For operation as a video camera, DSP 1070 can be adapted to convert thesequence of video frames captured by the image sensor 1032, into a videostream of a standard or proprietary video stream format (e.g., MJPEG,MPEG-4, or RealVideo™) before transmitting it to volatile memory 1080 orstorage memory 1084. The recorded video files can be played back via thedisplay 1097 or transmitted to an external computer.

Operational characteristics of an exemplary imaging terminal and itsprocessing of image signals are now further described. In response tocontrol signals received from processor 1060, timing and control circuit1038 can send image sensor array timing signals to array 1033 such asreset, exposure control, and readout timing signals. After an exposureperiod, a frame of image data can be read out. Analog image signals thatare read out of array 1033 can be amplified by gain block 1036 convertedinto digital form by analog-to-digital converter 1037 and sent to adigital signal processor (DSP) which can convert the image into anuncompressed RGB image format or a standard or proprietary image format(e.g., JPEG), before sending it to volatile memory 1080. In anotherembodiment, the raw image can be sent to the memory 1080 by ADC 1037,and the converting of the image into a standard or proprietary imageformat can be performed by processor 1060. Processor 1060 can addressframes of image data retained in RAM 1080 for decoding of decodableindicia represented therein.

A timing diagram further illustrating operation of terminal 1000, in oneembodiment, is shown in FIG. 26. Timeline 1202 shows a state of atrigger signal which may be made active by depression of trigger button1095. Terminal 1000 can also be adapted so that a trigger signal can bemade active by the terminal sensing that an object has been moved into afield of view thereof or by receipt of a serial command from an externalcomputer. Terminal 1000 can also be adapted so that a trigger signal ismade active by a power up of terminal 1000. For example, in oneembodiment, terminal 1000 can be supported on a scan stand and used forpresentation reading. In such an embodiment, terminal 1000 can beadapted so that a trigger signal represented by timeline 1202 can beactive for the entire time terminal 1000 is powered up. Terminal 1000can be adapted so that trigger signal 1202 can be maintained in anactive reading state (indicated by the signal 1202 remaining high) bymaintaining trigger button 1095 in a depressed position. In oneembodiment, where terminal 1000 is adapted to read decodable indicia,terminal 1000 can be adapted so that depressing trigger 1095 drivestrigger signal 1202 into an active state where it remains until theearlier of (a) the trigger button 1095 is released, or (b) a decodableindicia is successfully decoded.

With further reference to the timing diagram of FIG. 26, terminal 1000can be adapted so that after a trigger signal is made active at time1220, pixels of image sensor 1032 are exposed during first exposureperiod EXP₁ occurring during a first time period followed by secondexposure period EXP₂ occurring during a second time period, thirdexposure period EXP₃ occurring during a third time period and so on(after time 1220 and prior to first exposure period EXP₁, parameterdetermination frames subject to parameter determination processing maybe optionally captured subsequent to parameter determination exposureperiods that are not indicated in FIG. 26). Referring to the timingdiagram of FIG. 26, terminal 1000 may expose, capture, and subject tounsuccessful decode attempts N−1 frames of image data prior tosuccessfully decoding a frame of image data corresponding to exposureperiod EXP_(N). An exposure control signal in one embodiment isrepresented by timeline 1204 of FIG. 26.

Terminal 1000 can be adapted so that after pixels of image sensor array1033 are exposed during an exposure period, a readout control pulse isapplied to array 1033 to read out analog voltages from image sensor 1032representative of light incident on each pixel of a set of pixels ofarray 1033 during the preceding exposure period. Timeline 1206illustrates a timing of readout control pulses applied to image sensorarray 1033. A readout control pulse can be applied to image sensor array1033 after each exposure period EXP₁, EXP₂, EXP₃, EXP_(N-1), EXP_(N).Readout control pulse 1232 can be applied for reading out a frame ofimage data exposed during first exposure period EXP₁. Readout controlpulse 1234 can be applied for reading out a frame of image data exposedduring second exposure period EXP₂, and readout pulse 1236 can beapplied for reading out a frame of image data exposed during thirdexposure period, EXP₃. A readout control pulse 1238 can be applied forreading out a frame of image data exposed during exposure periodEXP_(N-1) and readout control pulse 1240 can be applied for reading outa frame of image data exposed during exposure period EXP_(N).

After analog voltages corresponding to pixels of image sensor array 1033are read out and digitized by analog-to-digital converter 1037,digitized pixel values corresponding to the voltages can be received byDSP 1070 and converted into a standard or proprietary image format(e.g., JPEG). In another embodiment, digitized pixel values captured byimage sensor array 1033 can be received into system volatile memory1080. Terminal 1000 can be adapted so that terminal 1000 can formatizeframes of image data. For example, terminal 1000 can be adapted so thatprocessor 1060 formats a selected frame of image data in a compressedimage file format, e.g., JPEG. In another embodiment, terminal 1000 canalso be adapted so that terminal 1000 formats frames of image data intoa video stream format (e.g., MJPEG, MPEG-4, or RealVideo™) fortransmitting to an external computer or for recording of digital movies.

Terminal 1000 can also be adapted so that processor 1060 can subject toa decode attempt a frame of image data retained in memory 1080. Forexample, in attempting to decode a ID bar code symbol represented in aframe of image data, processor 1060 can execute the following processes.First, processor 1060 can launch a scan line in a frame of image data,e.g., at a center of a frame, or a coordinate location determined toinclude a decodable indicia representation. Next, processor 1060 canperform a second derivative edge detection to detect edges. Aftercompleting edge detection, processor 1060 can determine data indicatingwidths between edges. Processor 1060 can then search for start/stopcharacter element sequences, and if found, derive element sequencecharacters character by character by comparing with a character settable. For certain symbologies, processor 1060 can also perform achecksum computation. If processor 1060 successfully determines allcharacters between a start/stop character sequence and successfullycalculates a checksum (if applicable), processor 1060 can output adecoded message. When outputting a decoded message, processor 1060 canone or more of (a) initiate transfer of the decoded message to anexternal device, (b) initiate display of a decoded message on a display1097 of terminal 1000, (c) attach a flag to a buffered decoded messagedetermined by processor 1060, and (d) write the decoded message to anaddress on long term memory, e.g., 1082 and/or 1084. At the time ofoutputting a decoded message, processor 1060 can send a signal to anacoustic output device 1078 of terminal 1000 to emit a beep.

Times at which terminal 1000, in one embodiment, attempts to decode adecodable indicia represented in a frame of image data are illustratedby periods 1332, 1334, 1336, 1338, and 1340 of timeline 1208 as shown inthe timing diagram of FIG. 26. Regarding timeline 1208, period 1332illustrates a period at which terminal 1000 attempts to decode a firstframe of image data having associated exposure period EXP₁, period 1334illustrates a period at which terminal 1000 attempts to decode a secondframe of image data having second exposure period EXP₂, period 1336illustrates a period at which terminal 1000 attempts to decode a thirdframe of image data having third exposure period EXP₃, period 1338illustrates a period at which terminal 1000 attempts to decode a frameof image data having an exposure period EXP_(N-1), while period 1340illustrates a period at which terminal 1000 attempts to decode an Nthframe of image data having exposure period EXP_(N). It is seen the“decode time” during which terminal 1000 attempts to decode a frame ofimage data can vary from frame to frame.

Terminal 1000 can be adapted so that lens assembly 500 has a pluralityof lens settings. It has been described that the various lens settingsof lens assembly 500 can be realized by applying a force to one or moredeformable lens elements. In one particular example, terminal 1000 canhave 7 lens settings. At each lens setting, lens assembly 500 andtherefore terminal 1000 can have a different plane of optical focus(best focus distance) and a different field of view, typically expressedby the parameter “half FOV” angle. The terminal best focus distances ateach of the seven lens settings in one particular example can be givenas follows: L1=2″, L2=5″, L3=9″, L4=14″, L5=20″, L6=27″, L7=35″, where“L1-L7” are lens settings “1” through “7.” Each different lens settingcan have a different associated focal length half FOV angle, and planeof nominal focus. In one aspect, terminal 1000 can be adapted to “cycle”between various lens settings according to a predetermined pattern,while a trigger signal remains active. In another aspect, terminal 1000can be adapted while a trigger signal remains active, to change settingsbetween various lens settings that are determined according to anadaptive pattern. For example, terminal 1000 can, while trigger signalremains active, change a lens setting of assembly 500 according to apattern which will enable terminal 1000 to establish an in-focus lenssetting without simply testing the degree of focus of each of asuccession of lens settings.

In another aspect, the timing of the movement of deformable lens element10 can be coordinated with exposure periods EXP₁, EXP₂ . . . EXP_(N), sothat the lens element 10 is not moved except for times intermediate ofthe exposure periods. Referring to timeline 1210, terminal 1000 can beadapted so that electrical signals are applied to actuator 20 to causemovement of actuator 20 and deformable lens element 10 in such mannerdeformable lens element 10 is in a moving state only during periods1432, 1434, 1436, 1438 1440, which are periods intermediate of theexposure periods EXP₁, EXP₂ . . . EXP_(N). When deformable lens element10 is controlled according to the timing diagram of FIG. 26, it is seenthat deformable lens element 10 will be in a static, non-moving stateduring each exposure period EXP₁, EXP₂ . . . EXP_(N).

An exemplary auto-focusing algorithm is described with reference to theflow diagram of FIG. 27. At block 1502 terminal 1000 can determinewhether a first frame, i.e., the frame having the exposure period EXP₁is in-focus. A determination of whether a frame is in-focus can includean examination of the “flatness” of a frame of image data. Plottingpixel values of a frame in a histogram, an out-of focus frame will havea relatively “flat” distribution of pixel value intensities with arelatively even distribution of intensities over a range of intensities.An in-focus frame, on the other hand can be expected to have, relativeto an out-of-focus frame, substantial incidences of pixel values atcertain intensities and substantially fewer incidences at otherintensities. If terminal 1000 at block 1502 determines that presentframe is in-focus terminal 1000 can proceed to block 1512 to maintainthe lens setting at the setting determined to be in-focus and cansubject the frame to processing. The processing can include, e.g.,subjecting the frame to an indicia decode attempt or outputting theframe to a display, possibly as a formatted single frame or as anoutputted frame of a formatted streaming video image.

If the frame examined at block 1502 is not in-focus, terminal 1000 atblock 1506 can examine a frame having a different focus setting than theframe of image data examined at block 1502. By a frame having a “certainlens setting” it is meant that the focus setting of lens assembly 500was set to the certain setting during the exposure period associated tothe frame. If terminal 1000 at block 1504 determines that the frameexamined at block 1504 is in-focus, terminal 1000 can proceed to block1512 to maintain the lens assembly 500 at the current setting (thesetting yielding to the frame determined to be in-focus) and process aframe or frames exposed with the lens assembly 500 at the determinedin-focus setting.

Further referring to the timing diagram of FIG. 27, if the frameexamined at block 1506 is determined at block 1508 to be not in-focusterminal 1000 can proceed to block 1510 to determine an in-focus settingbased on a processing of the first frame examined at block 1502 and thesecond frame examined at block 1504. Such processing can includeevaluating the impact on the flatness of a frame by changing a lenssetting (e.g., an algorithm may run so that if captured frame becomesmore flat [less in-focus] by moving the lens setting from a firstsetting to a second setting having a farther best focus distance thanthe first setting, the lens setting is set to a certain setting having ashorter best focus distance than the first setting responsively to theprocessing). When an in-focus setting has been determined, terminal 1000sets the lens assembly 500 to the determined in-focus setting and canadvance to block 1512 to process a frame(s) having exposure periodscoinciding with times at which the lens setting is set to the determinedin-focus setting. If the frame examined at block 1506 is determined atblock 1508 to be in-focus, terminal 1000 can proceed to block 1512 tomaintain the lens assembly 500 at the current setting and process aframe or frames exposed with the lens assembly 500 at the determinedin-focus setting.

Turing now to the view of FIG. 28, a mobile hand held housing 1091 forincorporating and supporting the components of FIG. 25 is shown anddescribed. The generic form factor of FIG. 28 represents the common formfactor of a mobile e.g., cellular telephone or a portable datacollection terminal for use in data collection applications. Terminal1000 can also incorporate a housing in other familiar form factors e.g.,a digital camera or a camcorder form factor.

As indicated by the displayed menu of display 1097 as shown in FIG. 28,terminal 1000 can have a plurality of operator-selectableconfigurations. Each configuration can have a different associated lenssetting control algorithm. That is, the method by which terminal 1000controls a lens setting of lens assembly 500 responsively to a triggersignal being made active changes depending on which configuration isselected.

Various operator selectable configurations are summarized in Table Dbelow. In configuration 1, terminal 1000 cycles between various lenssettings according to a predetermined pattern. Specifically inconfiguration 1, terminal 1000 changes a lens setting to a next lenssetting after each exposure period, and then decrements the lens settingby 1 after a frame has been captured using the maximum far focus setting(L7). In configuration 2, terminal 1000 responsively to a trigger signal1202 being made active changes lens settings of terminal 1000 accordingto an adaptive pattern. In Table D, the row entries of configuration 2illustrate a lens setting change pattern that might be exhibited byterminal 1000 when executing an auto-focus algorithm. For frame 1 andframe 2 (having associated exposure periods 1 and 2), the lens settingis advanced. However, after frames 1 and 2 are processed a subsequentframe e.g., frame 4 corresponding to EXP₄ might have a lens setting ofL2 if the processing of frames 1 and 2 indicates that setting L2 is anin-focus setting. In configuration 3, terminal 1000 does not change thelens setting but rather maintains the lens setting of terminal 1000 at afixed short focus position. Configuration 3 might be selected e.g.,where it is known that terminal 1000 will be used for fixed positionclose view indicia decoding. In configuration 4, terminal 1000 does notchange the lens setting responsively to a trigger signal beingmaintained in an active state; but rather maintains the lens setting atfar focus position. Configuration 4 might be useful e.g., where terminal1000 will be used to capture frames for image data corresponding to farfield objects. In configuration 5, terminal 1000 changes a lens settingadaptively until an in-focus lens setting is determined and thencaptures a predetermined number of frames using the in-focus setting.Configuration 5 might be useful e.g., where terminal 1000 is used tocapture still image frames of image data. From the row datacorresponding to configuration 5 in Table D it is seen that terminal1000 might process frames 1 and 2 to determine an in-focus setting, movethe lens setting to the determined in focus setting, capture a pluralityof frames at the in-focus setting, process the frames, and thendeactivate the trigger signal. The plurality of frames captured at thedetermined in-focus setting might be averaged or otherwise processed fornoise reduction. Regarding configuration 6, configuration 6 is similarto configuration 1, except that terminal 1000 when operating accordingto configuration 6 skips lens assembly settings and maintains the lenssetting at each successive setting for a plurality of frames beforeadvancing to a next setting. Regarding configuration 7, configuration 7illustrates operation of terminal 1000 when executing a simplifiedauto-focus algorithm in which terminal 1000 simply sequentially advancesthe lens setting for each new frame, tests the degree of focus of eachincoming frame, and maintains the frame at the first frame determined tobe in-focus. Note with respect to the exposure period EXP₄, terminal1000 might advance the lens setting to an un-focused setting while itprocesses the frame having the exposure period EXP₃.

TABLE D Configuration Exposure Period and Lens Setting Coordination 1Exposure Period 1 2 3 4 5 6 7 8 9 10 11 12 . . . Lens Setting L1 L2 L3L4 L5 L6 L7 L6 L5 L4 L3 L2 . . . 2 Exposure Period 1 2 3 4 5 6 7 8 9 1011 12 . . . Lens Setting L4 L5 L6 L7 L2 L2 L2 L2 L2 L2 L2 L2 . . . 3Exposure Period 1 2 3 4 5 6 7 8 9 10 11 12 . . . Lens Setting L1 L1 L1L1 L1 L1 L1 L1 L1 L1 L1 L1 . . . 4 Exposure Period 1 2 3 4 5 6 7 8 9 1011 12 . . . Lens Setting L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 L7 . . . 5Exposure Period 1 2 3 4 5 6 7 8 9 10 11 12 . . . Lens Setting L4 L5 L6L7 L3 L3 L3 . . . 6 Exposure Period 1 2 3 4 5 6 7 8 9 10 11 12 . . .Lens Setting L1 L1 L1 L3 L3 L3 L5 L5 L5 L7 L7 L7 . . . 7 Exposure Period1 2 3 4 5 6 7 8 9 10 11 12 . . . Lens Setting L1 L2 L3 L4 L3 L3 L3 L3 L3L3 L3 L3 . . .

A small sample of systems methods and apparatus that are describedherein is as follows:

A1. An apparatus for use in a lens assembly, said apparatus comprising:

a deformable lens element having an axis and a deformable surface, atleast part of which transmits image forming light rays; and

a force imparting structural member disposed to impart a force to saiddeformable surface;

wherein said apparatus is adapted so that said force impartingstructural member is capable of imparting at least one of a pushingforce or a pulling force to said deformable surface.

A2. The apparatus of claim A1, wherein said force imparting structuralmember is adapted to impart a force to said deformable surface at aplurality of force impartation points formed in a ring pattern spacedapart from and peripherally disposed about said axis.

A3. The apparatus of claim A1, wherein said force imparting structuralmember is adapted to impart a force to said deformable surface at aplurality of force impartation points formed in an area pattern aboutsaid axis. A4. The apparatus of claim A1, wherein said force impartingstructural member is an actuator. A5. The apparatus of claim A1, whereinsaid force imparting structural member is a structural member thattransmits force generated by an actuator. A6. The apparatus of claim A1,wherein said force imparting structural member imparts a force generallyin a direction of said axis. A7. The apparatus of claim A1, wherein saiddeformable surface partially defines a cavity that holds focus fluid.A8. The apparatus of claim A1, wherein a major body of said deformablelens element comprises a resiliently deformable material member, andwherein said deformable lens element is devoid of a focus fluid. A9. Theapparatus of claim A1, wherein said apparatus is adapted so that saidstructural member is capable of imparting both of said pushing force andsaid pulling force to said deformable surface. A10. The apparatus ofclaim A1, wherein said apparatus is adapted so that said structuralmember is capable of imparting a pulling force to said deformablesurface.

B1. An apparatus for use in a lens assembly, said apparatus comprising:

a deformable lens element having an axis and a deformable surface, atleast part of which transmits image forming light rays; and

a force imparting structural member disposed to impart a force to saiddeformable surface;

wherein said apparatus is adapted so that said force impartingstructural member is capable of imparting a pushing force to saiddeformable surface resulting in a thickness of said deformable lensmember along a plurality of imaginary lines running in parallel withsaid imaging axis decreasing.

B2. The apparatus of claim B1, wherein said apparatus is adapted so thatwhen said pushing force is imparted to said deformable surface, saiddeformable surface bulges outward in an area of said deformable surfaceabout said axis.

B3. The apparatus of claim B1, wherein said apparatus is adapted so thatsaid plurality of imaginary lines along which said thickness of saiddeformable lens element decreases do not include a plurality ofimaginary lines running parallel with said imaging axis and intersectingsaid deformable surface within an area delimited by a ring shapedpattern spaced apart from and peripherally disposed about said axis.

B4. The apparatus of claim B1, wherein said plurality of imaginary linesinclude imaginary lines disposed about said axis.

C1. An apparatus for use in a lens assembly, said apparatus comprising:

a deformable lens element having an axis and a deformable surface, atleast part of which transmits image forming light rays; and

a force imparting structural member disposed to impart a force to saiddeformable surface;

wherein said apparatus is adapted so that said force impartingstructural member is capable of imparting one or more of the followingto said deformable surface:

-   -   (a) a pushing force resulting in the deformable surface bulging        outward in an area of said deformable surface about said axis;        and    -   (b) a pulling force resulting in a shape of said deformable        surface changing.

C2. The apparatus of claim C1, wherein said deformable surface iscapable of a concave configuration and wherein said pulling forceincreases a concavity of said deformable surface. C3. The apparatus ofclaim C1, wherein said deformable surface is capable of a convexconfiguration and wherein said pushing force increases a convexity ofsaid deformable surface. C4. The apparatus of claim C1, wherein saidapparatus is adapted so that said force imparting member is capable ofimparting each of said pushing force and said pulling force on saiddeformable surface. C5. The apparatus of claim C1, wherein at least oneof said pushing force and said pulling force are generated by anelectro-active polymer actuator. C6. The apparatus of claim C1, whereinat least one of said pushing force and said pulling force is imparted ina direction generally in a direction of said axis. C7. The apparatus ofclaim C1, wherein a major body of said deformable lens member comprisesa resiliently deformable material member. C8. The apparatus of claim C1,wherein said deformable surface partially defines a cavity filled withfocus fluid. C9. The apparatus of claim C1, wherein said pushing forceresults in a thickness of said deformable lens member decreasing alongan imaginary line running in parallel with and being spaced apart fromsaid axis.

C10. The apparatus of claim C1, wherein said pushing force results in athickness of said deformable lens member decreasing along a plurality ofimaginary lines running in parallel with and being spaced apart fromsaid axis, the plurality of imaginary lines being peripherally disposedabout said axis.D1. An apparatus for use in a lens assembly, said apparatus comprising:

a deformable lens member having an axis and a deformable surface, atleast part of which transmits image forming light rays; and

a force imparting structural member disposed to impart a force to saiddeformable surface;

wherein said apparatus is adapted so that said force impartingstructural member is capable of imparting a pushing force to saiddeformable surface resulting in a thickness of said deformable lensmember along said axis decreasing.

D2. The apparatus of claim D1, wherein said force imparting member isconfigured to impart said pushing force to said deformable surface at aplurality of force impartation points that include an area about saidaxis, the force imparting member being optically clear for transmittalof image forming light rays.

D3. The apparatus of claim D1, wherein said deformable lens member isnormally convex in an unstressed state thereof. D4. The apparatus ofclaim D1, wherein said force imparting structural member imparts a forceto said deformable surface at a plurality of points definedsubstantially over an entire area of said deformable surface. D5. Theapparatus of claim D1, wherein a major body of said deformable lensmember is provided by a resiliently deformable material member. D6. Theapparatus of claim D1, wherein said force is generated by anelectro-active polymer actuator having an optically clear area disposedabout said axis.

D7. The apparatus of claim D1, wherein said force is generated by anelectro-active polymer actuator comprising a flexible membersubstantially conforming to a shape of the deformable surface, theflexible member having an optically clear area disposed about said axis.

D8. The apparatus of claim D1, wherein said apparatus is adapted so thatsaid pushing force is imparted in a direction generally in a directionof said axis.

E1. A method comprising:

incorporating a deformable lens element into an optical system, saiddeformable lens element having a deformable surface, at least part ofwhich transmits image forming light rays; and

imparting a force to said deformable surface of said deformable lenselement at a plurality of force impartation points of said surface tovary an optical characteristic of said optical system, wherein saidimparting step includes the step of utilizing a force impartingstructural member for imparting said force.

E2. The method of claim E1, wherein said imparting step includes thestep of utilizing an electro-active polymer actuator. E3. The method ofclaim E1, wherein said deformable lens element has an axis, and whereinsaid imparting step includes the step imparting said force generally inthe direction of said axis. E4. The method of claim E1, wherein saidplurality of force imparting points are defined in a ring pattern onsaid surface peripherally disposed about and spaced apart from saidaxis. E5. The method of claim E1, wherein said plurality of forceimparting points define a two dimensional area about said axis. E7. Themethod of claim E1, wherein said force is a push force directed towardsaid deformable lens element. E8. The method of claim E1, wherein saidforce is a pull force directed away from said deformable lens element.

F1. A method comprising:

incorporating a deformable lens element having an axis into an opticalsystem, said deformable lens element having a deformable lens surface atleast a part of which transmits image forming light rays; and

imparting a pulling force to said deformable surface of said deformablelens element to vary an optical characteristic of said optical system,wherein said imparting step includes the step of imparting said pullingforce generally in a direction of said axis.

F2. The method of claim F1, wherein said imparting step includes thestep of utilizing an electro-active polymer actuator. F3. The method ofclaim F1, wherein said imparting step includes the step of impartingsaid pulling force at a plurality of points spaced apart from andperipherally disposed about said axis. F4. The method of claim F1,wherein said imparting step includes the step of utilizing a structuralmember.

G1. An optical imaging system comprising:

a deformable lens element having a deformable surface at least part ofwhich transmits image forming light rays;

a force imparting structural member opposing said surface; and

wherein said imaging system is adapted so that a force can be impartedby said force imparting structural member at a plurality of forceimpartation points of said deformable surface of said deformable lenselement for varying an optical characteristic of said imaging system.

G2. The optical imaging system of claim G1, wherein said forceimpartation points are defined in an area pattern about an axis of saiddeformable lens element. G3. The optical imaging system of claim G1,wherein said force impartation points are defined in a ring patterndefined at positions spaced apart from and peripherally disposed aboutsaid axis.

H1. An optical imaging system comprising:

a deformable lens element comprising a deformable membrane, a cavitydelimited by said deformable membrane, and fluid disposed in saidcavity, said fluid having an index of refraction greater than one, saiddeformable lens element having an axis; and

a force imparting structural member capable of contact with saiddeformable lens element at positions defined circumferentially aboutsaid axis;

wherein said optical imaging system is configured so that said forceimparting structural member can be moved generally in a direction ofsaid axis either toward or away from said deformable lens element sothat an optical characteristic of said imaging system varies withmovement of said force imparting structural member.

H2. The optical imaging system of claim H1, wherein said force impartingstructural member is provided by a ring-shaped pressure element. H3. Theoptical imaging system of claim H1, wherein said force impartingstructural member is provided by a plurality of tab-like elements of anelectro-active polymer actuator. H4. The optical imaging system of claimH1, wherein said force imparting structural member is provided by aflexible member of an electro-active polymer.

I1. An optical imaging system comprising:

a deformable lens element comprising a deformable membrane, a cavitydelimited by said deformable membrane, and fluid disposed in saidcavity, said fluid having an index of refraction greater than one, saiddeformable lens element having an axis, a ring-shaped pressure elementin contact with said deformable lens element and arrangedcircumferentially about said axis; and

an electro-active polymer actuator mechanically coupled to saidring-shaped pressure element, said optical imaging system beingconfigured so that said electro-active polymer actuator moves saidring-shaped pressure element generally in a direction of said axis sothat an optical characteristic of said imaging system varies withmovement of said ring-shaped pressure element.

I2. The optical imaging system of claim I1, wherein said electro-activepolymer actuator includes a ring-shaped deformable element comprising aplurality of tab-like elements, said deformable element beingcircumferentially disposed about said axis, said plurality of tab-likeelements engaging said ring shaped pressure element.J1. An optical imaging system comprising:

a deformable lens element having an axis, wherein a major body of saiddeformable lens element is provided by a resiliently deformable memberhaving a hardness measurement of less than Shore A 60; and

wherein said imaging system is configured so that a force can be appliedto an external surface of said deformable lens for varying an opticalcharacteristic of said imaging system.

J2. The optical imaging system of claim J1, wherein said optical imagingsystem includes an flexible member actuator for imparting said force,said actuator having a flexible member adapted to substantially conformto a shape of said deformable lens element.K1. An optical system for use in imaging an object, said systemcomprising:

a deformable lens element capable of being deformed wherein saiddeformable lens element has a deformable surface that faces an exteriorof said deformable lens element, said deformable lens element having anaxis;

wherein said optical system is adapted so that said system can impart aforce to said deformable surface generally in a direction of said axistoward said deformable lens element in such manner that an opticalproperty of said deformable lens element is changed by impartation ofsaid force.

K2. The optical system of claim K1, wherein said optical system isadapted so that said system imparts said force at a plurality ofpositions spaced apart from and peripherally disposed about said imagingaxis. K3. The optical system of claim K1, wherein said optical systemincludes an actuator including an aperture disposed about said axis forimparting said force to said deformable lens element generally in adirection of said axis.

L1. An optical system for use in imaging an object, said systemcomprising:

a deformable lens element having a deformable lens surface, at leastpart of which transmits image forming light rays and which faces anexterior of said deformable lens element, said deformable lens surfacebeing one of normally convex or capable of exhibiting a convexcurvature, said deformable lens element having an axis; and

an actuator for imparting a force to said deformable surface, theactuator having an aperture disposed about said axis, the optical systembeing adapted so that actuation of said actuator results in a forcebeing imparted to said deformable surface to vary a convexity of saiddeformable lens element.

L2. The optical system of claim L1, wherein said optical system includesa pressure element transferring a force generated by said actuator tosaid deformable lens element.

L3. The optical system of claim L1 wherein said deformable lens elementis configured so that, for achieving deformation thereof, saiddeformable lens element is contacted at a plurality of positions spacedapart from and peripherally disposed about said axis.

L4. The optical system of claim L1, wherein said optical system includesa force imparting structural member for imparting a force generated bysaid actuator and for imparting said force generated by said actuator tosaid deformable surface. L5. The focus apparatus of claim L4, whereinsaid force imparting structural element is said actuator.

M1. A hand held data collection terminal comprising:

a two dimensional image sensor comprising a plurality of pixels formedin a plurality of rows and columns of pixels;

an imaging lens assembly comprising a deformable lens element forfocusing an image onto said two dimensional image sensor, said imaginglens being adapted so that said deformable lens element can be deformedwith use of a force imparting structural member, said imaging lensassembly being adapted so that force can be applied to an externalsurface of said deformable lens element to vary an optical property ofsaid deformable lens element, said imaging lens setting having a firstlens setting at which said deformable lens element is in a first stateand a second lens setting at which said deformable lens element is in asecond state; and

a trigger for activating a trigger signal, said data collection terminalbeing adapted so that said trigger signal can be maintained in an activestate by maintaining said trigger in a depressed position;

wherein said data collection terminal is adapted so that responsively tosaid trigger signal being maintained in said active state, said datacollection terminal captures in succession a plurality of frames ofimage data, each of said plurality of frames of image data representinglight incident on said image sensor at an instant in time, wherein saiddata collection terminal is adapted so that a lens setting of saidimaging lens assembly is varied while said trigger signal is maintainedin said active state in such manner that said lens assembly is at saidfirst setting for an exposure period corresponding to at least one ofsaid plurality of frames of image data, and said lens assembly is atsaid second lens setting for an exposure period corresponding to atleast one of said plurality of frames of image data.

M2. The hand held data collection terminal of claim M1, wherein saiddata collection terminal is adapted so that said data collectionterminal subjects to an indicia decode attempt more than one of saidplurality of frames of image data.

N1. A focus apparatus comprising:

a deformable lens element having an axis, wherein a major body of saiddeformable lens element comprises a resiliently deformable member havingat least one normally convex lens surface; and

an actuator for deforming said deformable lens element, the actuatorhaving a flexible member adapted to substantially conform to a shape ofsaid convex lens surface and having one of a coated area or an aperturedisposed about said axis, the focus apparatus being adapted so that byvarying a voltage applied to said flexible member a convexity of saidnormally convex lens surface changes.

N2. The focus apparatus of claim N1, wherein said resiliently deformablemember has a hardness of less then about Shore A 60. N3. The focusapparatus of claim N1, wherein said resiliently deformable member has ahardness of less than about Shore A 20. N4. The focus apparatus of claimN1, wherein said resiliently deformable member comprises silicon gel.N5. The focus apparatus of claim N1, wherein said deformable lenselement is a one piece element consisting of said resiliently deformablemember. N6. The focus apparatus of claim N1, wherein said flexiblemember is a flexible member interposed between a pair of flexibleelectrodes.

O1. A focus apparatus comprising:

a deformable lens element having an axis, wherein a major body of saiddeformable lens element comprises a resiliently deformable member havingat least one convex lens surface; and

an actuator for imparting a force to said deformable lens element todeform said deformable lens element and to change an optical property ofsaid deformable lens element.

O2. The focus apparatus of claim O1, wherein said actuator has anaperture disposed about said axis, said actuator being selected from thegroup consisting of an ion conductive electro-active polymer actuator, adielectric electro-active polymer actuator, and a hollow stepper motor.O3. The focus apparatus of claim O1, wherein said deformable lenselement has a deformable surface, at least part of which transmits imageforming light rays, and where said focus apparatus includes a forceimparting structural element imparting a force generated by saidactuator to said deformable surface.

O4. The focus apparatus of claim O3, wherein said force impartingstructural element is said actuator. P1. A focus apparatus for use in anoptical imaging system, said focus apparatus comprising;

a deformable lens element having a deformable light entry surface and anopposing deformable light exit surface, the deformable lens elementhaving an axis intersecting respective centers of said deformable lightentry surface and said opposing deformable light exit surface;

a first actuator for deforming said deformable light entry surface tochange an optical property of said deformable lens element; and

a second actuator for deforming said deformable light exit surface tochange an optical property of said deformable lens element.

P2. The focus apparatus of claim P1, wherein at least one of said firstand second actuators is an electro-active polymer actuator. P3. Thefocus apparatus of claim P1, wherein at least one of said first andsecond actuators has an aperture disposed about said axis. P4. The focusapparatus of claim P1, wherein said focus apparatus is adapted so that aforce generated by at least one of said first and second actuators istransferred to said deformable lens element by a push ring. P5. Thefocus apparatus of claim P1, wherein said deformable lens elementconsists of a one piece resiliently deformable member. P6. The focusapparatus of claim P1, wherein said deformable lens element has a cavityand focus fluid disposed in said cavity.

P7. The focus apparatus of said claim P1, wherein said focus apparatusincludes a first deformable membrane defining said light entry surfaceand second deformable membrane defining said second light entry surface,a window, first cavity delimited by said first deformable membrane andsaid window, a second cavity delimited by said second deformablemembrane and said window, and focus fluid disposed in each of said firstand second cavities.P8. The focus apparatus of claim P1, wherein said focus apparatus isadapted so that a force generated by at least one of said first andsecond actuators is imparted to said deformable lens element at aplurality of points spaced apart from and peripherally disposed aboutsaid axis.Q1. A deformable lens element comprising:

a first clamping element, the first clamping element including a rigidtransparent member having an optical surface for allowing light rays topass there through;

a deformable membrane;

a second clamping member clamping said deformable membrane against saidfirst clamping element so that said deformable membrane opposes saidrigid transparent optical surface;

a cavity delimited by said deformable membrane and said first clampingelement; and

a deformable substance having an index of refraction greater than onedisposed in said cavity.

Q2. The deformable lens element of claim Q1, wherein said deformablesubstance is provided by a resiliently deformable member. Q3. Thedeformable lens element of claim Q1, wherein said deformable substancecomprises a focus fluid. Q4. The deformable lens element of claim Q1,wherein said optical surface is a curved surface having an opticalpower. Q5. The deformable lens element of claim Q1, wherein said opticalsurface is a planar optical surface. Q6. The deformable lens element ofclaim Q1, wherein said second clamping element is ultrasonically weldedto said second clamping element. Q7. The deformable lens element ofclaim Q1, wherein at least one of said clamping elements has an annulartooth ring for increasing a securing force between said first and secondclamping elements.

While the present invention has been described with reference to anumber of specific embodiments, it will be understood that the truespirit and scope of the invention should be determined only with respectto claims that can be supported by the present specification. Further,while in numerous cases herein wherein systems and apparatuses andmethods are described as having a certain number of elements it will beunderstood that such systems, apparatuses and methods can be practicedwith fewer than the mentioned certain number of elements.

1. An apparatus for use in a lens assembly, said apparatus comprising: adeformable lens element having an axis and a deformable surface, atleast part of which transmits image forming light rays; and a forceimparting structural member disposed to impart a force to saiddeformable surface; wherein said apparatus is adapted so that said forceimparting structural member is capable of imparting at least one of apushing force or a pulling force to said deformable surface.
 2. Theapparatus of claim 1, wherein said force imparting structural member isadapted to impart a force to said deformable surface at a plurality offorce impartation points formed in a ring pattern spaced apart from andperipherally disposed about said axis.
 3. The apparatus of claim 1,wherein said force imparting structural member is adapted to impart aforce to said deformable surface at a plurality of force impartationpoints formed in an area pattern about said axis.
 4. The apparatus ofclaim 1, wherein said force imparting structural member is an actuator.5. The apparatus of claim 1, wherein said force imparting structuralmember is a structural member that transmits force generated by anactuator.
 6. The apparatus of claim 1, wherein said force impartingstructural member imparts a force generally in a direction of said axis.7. The apparatus of claim 1, wherein said deformable surface partiallydefines a cavity that holds focus fluid.
 8. The apparatus of claim 1,wherein a major body of said deformable lens element comprises aresiliently deformable material member, and wherein said deformable lenselement is devoid of a focus fluid.
 9. The apparatus of claim 1, whereinsaid apparatus is adapted so that said structural member is capable ofimparting both of said pushing force and said pulling force to saiddeformable surface.
 10. The apparatus of claim 1, wherein said apparatusis adapted so that said structural member is capable of imparting apulling force to said deformable surface.
 11. An apparatus for use in alens assembly, said apparatus comprising: a deformable lens elementhaving an axis and a deformable surface, at least part of whichtransmits image forming light rays; and a force imparting structuralmember disposed to impart a force to said deformable surface; whereinsaid apparatus is adapted so that said force imparting structural memberis capable of imparting a pushing force to said deformable surfaceresulting in a thickness of said deformable lens member along aplurality of imaginary lines running in parallel with said imaging axisdecreasing.
 12. The apparatus of claim 11, wherein said apparatus isadapted so that when said pushing force is imparted to said deformablesurface, said deformable surface bulges outward in an area of saiddeformable surface about said axis.
 13. The apparatus of claim 11,wherein said apparatus is adapted so that said plurality of imaginarylines along which said thickness of said deformable lens elementdecreases do not include a plurality of imaginary lines running parallelwith said imaging axis and intersecting said deformable surface withinan area delimited by a ring shaped pattern spaced apart from andperipherally disposed about said axis.
 14. The apparatus of claim 11,wherein said plurality of imaginary lines include imaginary linesdisposed about said axis.
 15. An apparatus for use in a lens assembly,said apparatus comprising: a deformable lens element having an axis anda deformable surface, at least part of which transmits image forminglight rays; and a force imparting structural member disposed to impart aforce to said deformable surface; wherein said apparatus is adapted sothat said force imparting structural member is capable of imparting oneor more of the following to said deformable surface: (a) a pushing forceresulting in the deformable surface bulging outward in an area of saiddeformable surface about said axis; and (b) a pulling force resulting ina shape of said deformable surface changing.
 16. The apparatus of claim15, wherein said deformable surface is capable of a concaveconfiguration and wherein said pulling force increases a concavity ofsaid deformable surface.
 17. The apparatus of claim 15, wherein saiddeformable surface is capable of a convex configuration and wherein saidpushing force increases a convexity of said deformable surface.
 18. Theapparatus of claim 15, wherein said apparatus is adapted so that saidforce imparting member is capable of imparting each of said pushingforce and said pulling force on said deformable surface.
 19. Theapparatus of claim 15, wherein at least one of said pushing force andsaid pulling force are generated by an electro-active polymer actuator.20. The apparatus of claim 15, wherein at least one of said pushingforce and said pulling force is imparted in a direction generally in adirection of said axis.
 21. The apparatus of claim 15, wherein a majorbody of said deformable lens member comprises a resiliently deformablematerial member.
 22. The apparatus of claim 15, wherein said deformablesurface partially defines a cavity filled with focus fluid.
 23. Theapparatus of claim 15, wherein said pushing force results in a thicknessof said deformable lens member decreasing along an imaginary linerunning in parallel with and being spaced apart from said axis.
 24. Theapparatus of claim 15, wherein said pushing force results in a thicknessof said deformable lens member decreasing along a plurality of imaginarylines running in parallel with and being spaced apart from said axis,the plurality of imaginary lines being peripherally disposed about saidaxis.
 25. An apparatus for use in a lens assembly, said apparatuscomprising: a deformable lens member having an axis and a deformablesurface, at least part of which transmits image forming light rays; anda force imparting structural member disposed to impart a force to saiddeformable surface; wherein said apparatus is adapted so that said forceimparting structural member is capable of imparting a pushing force tosaid deformable surface resulting in a thickness of said deformable lensmember along said axis decreasing.
 26. The apparatus of claim 25,wherein said force imparting member is configured to impart said pushingforce to said deformable surface at a plurality of force impartationpoints that include an area about said axis, the force imparting memberbeing optically clear for transmittal of image forming light rays. 27.The apparatus of claim 25, wherein said deformable lens member isnormally convex in an unstressed state thereof.
 28. The apparatus ofclaim 25, wherein said force imparting structural member imparts a forceto said deformable surface at a plurality of points definedsubstantially over an entire area of said deformable surface.
 29. Theapparatus of claim 25, wherein a major body of said deformable lensmember is provided by a resiliently deformable material member.
 30. Theapparatus of claim 25, wherein said force is generated by anelectro-active polymer actuator having an optically clear area disposedabout said axis.
 31. The apparatus of claim 25, wherein said force isgenerated by an electro-active polymer actuator comprising a flexiblemember substantially conforming to a shape of the deformable surface,the flexible member having an optically clear area disposed about saidaxis.
 32. The apparatus of claim 25, wherein said apparatus is adaptedso that said pushing force is imparted in a direction generally in adirection of said axis.
 33. A method comprising: incorporating adeformable lens element into an optical system, said deformable lenselement having a deformable surface, at least part of which transmitsimage forming light rays; and imparting a force to said deformablesurface of said deformable lens element at a plurality of forceimpartation points of said surface to vary an optical characteristic ofsaid optical system, wherein said imparting step includes the step ofutilizing a force imparting structural member for imparting said force.34. The method of claim 33, wherein said imparting step includes thestep of utilizing an electro-active polymer actuator.
 35. The method ofclaim 33, wherein said deformable lens element has an axis, and whereinsaid imparting step includes the step imparting said force generally inthe direction of said axis.
 36. The method of claim 33, wherein saidplurality of force imparting points are defined in a ring pattern onsaid surface peripherally disposed about and spaced apart from saidaxis.
 37. The method of claim 33, wherein said plurality of forceimparting points define a two dimensional area about said axis.
 38. Themethod of claim 33, wherein said force is a push force directed towardsaid deformable lens element.
 39. The method of claim 33, wherein saidforce is a pull force directed away from said deformable lens element.40. A method comprising: incorporating a deformable lens element havingan axis into an optical system, said deformable lens element having adeformable lens surface at least a part of which transmits image forminglight rays; and imparting a pulling force to said deformable surface ofsaid deformable lens element to vary an optical characteristic of saidoptical system, wherein said imparting step includes the step ofimparting said pulling force generally in a direction of said axis. 41.The method of claim 40, wherein said imparting step includes the step ofutilizing an electro-active polymer actuator.
 42. The method of claim40, wherein said imparting step includes the step of imparting saidpulling force at a plurality of points spaced apart from andperipherally disposed about said axis.
 43. The method of claim 40,wherein said imparting step includes the step of utilizing a structuralmember.
 44. An optical imaging system comprising: a deformable lenselement having a deformable surface at least part of which transmitsimage forming light rays; a force imparting structural member opposingsaid surface; and wherein said imaging system is adapted so that a forcecan be imparted by said force imparting structural member at a pluralityof force impartation points of said deformable surface of saiddeformable lens element for varying an optical characteristic of saidimaging system.
 45. The optical imaging system of claim 44, wherein saidforce impartation points are defined in an area pattern about an axis ofsaid deformable lens element.
 46. The optical imaging system of claim44, wherein said force impartation points are defined in a ring patterndefined at positions spaced apart from and peripherally disposed aboutsaid axis.
 47. An optical imaging system comprising: a deformable lenselement comprising a deformable membrane, a cavity delimited by saiddeformable membrane, and fluid disposed in said cavity, said fluidhaving an index of refraction greater than one, said deformable lenselement having an axis; and a force imparting structural member capableof contact with said deformable lens element at positions definedcircumferentially about said axis; wherein said optical imaging systemis configured so that said force imparting structural member can bemoved generally in a direction of said axis either toward or away fromsaid deformable lens element so that an optical characteristic of saidimaging system varies with movement of said force imparting structuralmember.
 48. The optical imaging system of claim 47, wherein said forceimparting structural member is provided by a ring-shaped pressureelement.
 49. The optical imaging system of claim 47, wherein said forceimparting structural member is provided by a plurality of tab-likeelements of an electro-active polymer actuator.
 50. The optical imagingsystem of claim 47, wherein said force imparting structural member isprovided by a flexible member of an electro-active polymer.
 51. Anoptical imaging system comprising: a deformable lens element comprisinga deformable membrane, a cavity delimited by said deformable membrane,and fluid disposed in said cavity, said fluid having an index ofrefraction greater than one, said deformable lens element having anaxis, a ring-shaped pressure element in contact with said deformablelens element and arranged circumferentially about said axis; and anelectro-active polymer actuator mechanically coupled to said ring-shapedpressure element, said optical imaging system being configured so thatsaid electro-active polymer actuator moves said ring-shaped pressureelement generally in a direction of said axis so that an opticalcharacteristic of said imaging system varies with movement of saidring-shaped pressure element.
 52. The optical imaging system of claim51, wherein said electro-active polymer actuator includes a ring-shapeddeformable element comprising a plurality of tab-like elements, saiddeformable element being circumferentially disposed about said axis,said plurality of tab-like elements engaging said ring shaped pressureelement.
 53. An optical imaging system comprising: a deformable lenselement having an axis, wherein a major body of said deformable lenselement is provided by a resiliently deformable member having a hardnessmeasurement of less than Shore A 60; and wherein said imaging system isconfigured so that a force can be applied to an external surface of saiddeformable lens for varying an optical characteristic of said imagingsystem.
 54. The optical imaging system of claim 53, wherein said opticalimaging system includes an flexible member actuator for imparting saidforce, said actuator having a flexible member adapted to substantiallyconform to a shape of said deformable lens element.
 55. An opticalsystem for use in imaging an object, said system comprising: adeformable lens element capable of being deformed wherein saiddeformable lens element has a deformable surface that faces an exteriorof said deformable lens element, said deformable lens element having anaxis; wherein said optical system is adapted so that said system canimpart a force to said deformable surface generally in a direction ofsaid axis toward said deformable lens element in such manner that anoptical property of said deformable lens element is changed byimpartation of said force.
 56. The optical system of claim 55, whereinsaid optical system is adapted so that said system imparts said force ata plurality of positions spaced apart from and peripherally disposedabout said imaging axis.
 57. The optical system of claim 55, whereinsaid optical system includes an actuator including an aperture disposedabout said axis for imparting said force to said deformable lens elementgenerally in a direction of said axis.
 58. An optical system for use inimaging an object, said system comprising: a deformable lens elementhaving a deformable lens surface, at least part of which transmits imageforming light rays and which faces an exterior of said deformable lenselement, said deformable lens surface being one of normally convex orcapable of exhibiting a convex curvature, said deformable lens elementhaving an axis; and an actuator for imparting a force to said deformablesurface, the actuator having an aperture disposed about said axis, theoptical system being adapted so that actuation of said actuator resultsin a force being imparted to said deformable surface to vary a convexityof said deformable lens element.
 59. The optical system of claim 58,wherein said optical system includes a pressure element transferring aforce generated by said actuator to said deformable lens element. 60.The optical system of claim 58 wherein said deformable lens element isconfigured so that, for achieving deformation thereof, said deformablelens element is contacted at a plurality of positions spaced apart fromand peripherally disposed about said axis.
 61. The optical system ofclaim 58, wherein said optical system includes a force impartingstructural member for imparting a force generated by said actuator andfor imparting said force generated by said actuator to said deformablesurface.
 62. The focus apparatus of claim 61, wherein said forceimparting structural element is said actuator.
 63. A hand held datacollection terminal comprising: a two dimensional image sensorcomprising a plurality of pixels formed in a plurality of rows andcolumns of pixels; an imaging lens assembly comprising a deformable lenselement for focusing an image onto said two dimensional image sensor,said imaging lens being adapted so that said deformable lens element canbe deformed with use of a force imparting structural member, saidimaging lens assembly being adapted so that force can be applied to anexternal surface of said deformable lens element to vary an opticalproperty of said deformable lens element, said imaging lens settinghaving a first lens setting at which said deformable lens element is ina first state and a second lens setting at which said deformable lenselement is in a second state; and a trigger for activating a triggersignal, said data collection terminal being adapted so that said triggersignal can be maintained in an active state by maintaining said triggerin a depressed position; wherein said data collection terminal isadapted so that responsively to said trigger signal being maintained insaid active state, said data collection terminal captures in successiona plurality of frames of image data, each of said plurality of frames ofimage data representing light incident on said image sensor at aninstant in time, wherein said data collection terminal is adapted sothat a lens setting of said imaging lens assembly is varied while saidtrigger signal is maintained in said active state in such manner thatsaid lens assembly is at said first setting for an exposure periodcorresponding to at least one of said plurality of frames of image data,and said lens assembly is at said second lens setting for an exposureperiod corresponding to at least one of said plurality of frames ofimage data.
 64. The hand held data collection terminal of claim 63,wherein said data collection terminal is adapted so that said datacollection terminal subjects to an indicia decode attempt more than oneof said plurality of frames of image data.
 65. A focus apparatuscomprising: a deformable lens element having an axis, wherein a majorbody of said deformable lens element comprises a resiliently deformablemember having at least one normally convex lens surface; and an actuatorfor deforming said deformable lens element, the actuator having aflexible member adapted to substantially conform to a shape of saidconvex lens surface and having one of a coated area or an aperturedisposed about said axis, the focus apparatus being adapted so that byvarying a voltage applied to said flexible member a convexity of saidnormally convex lens surface changes.
 66. The focus apparatus of claim65, wherein said resiliently deformable member has a hardness of lessthen about Shore A
 60. 67. The focus apparatus of claim 65, wherein saidresiliently deformable member has a hardness of less than about Shore A20.
 68. The focus apparatus of claim 65, wherein said resilientlydeformable member comprises silicon gel.
 69. The focus apparatus ofclaim 65, wherein said deformable lens element is a one piece elementconsisting of said resiliently deformable member.
 70. The focusapparatus of claim 65, wherein said flexible member is a flexible memberinterposed between a pair of flexible electrodes.
 71. A focus apparatuscomprising: a deformable lens element having an axis, wherein a majorbody of said deformable lens element comprises a resiliently deformablemember having at least one convex lens surface; and an actuator forimparting a force to said deformable lens element to deform saiddeformable lens element and to change an optical property of saiddeformable lens element.
 72. The focus apparatus of claim 71, whereinsaid actuator has an aperture disposed about said axis, said actuatorbeing selected from the group consisting of an ion conductiveelectro-active polymer actuator, a dielectric electro-active polymeractuator, and a hollow stepper motor.
 73. The focus apparatus of claim71, wherein said deformable lens element has a deformable surface, atleast part of which transmits image forming light rays, and where saidfocus apparatus includes a force imparting structural element impartinga force generated by said actuator to said deformable surface.
 74. Thefocus apparatus of claim 73, wherein said force imparting structuralelement is said actuator.
 75. A focus apparatus for use in an opticalimaging system, said focus apparatus comprising; a deformable lenselement having a deformable light entry surface and an opposingdeformable light exit surface, the deformable lens element having anaxis intersecting respective centers of said deformable light entrysurface and said opposing deformable light exit surface; a firstactuator for deforming said deformable light entry surface to change anoptical property of said deformable lens element; and a second actuatorfor deforming said deformable light exit surface to change an opticalproperty of said deformable lens element.
 76. The focus apparatus ofclaim 75, wherein at least one of said first and second actuators is anelectro-active polymer actuator.
 77. The focus apparatus of claim 75,wherein at least one of said first and second actuators has an aperturedisposed about said axis.
 78. The focus apparatus of claim 75, whereinsaid focus apparatus is adapted so that a force generated by at leastone of said first and second actuators is transferred to said deformablelens element by a push ring.
 79. The focus apparatus of claim 75,wherein said deformable lens element consists of a one piece resilientlydeformable member.
 80. The focus apparatus of claim 75, wherein saiddeformable lens element has a cavity and focus fluid disposed in saidcavity.
 81. The focus apparatus of said claim 75, wherein said focusapparatus includes a first deformable membrane defining said light entrysurface and second deformable membrane defining said second light entrysurface, a window, first cavity delimited by said first deformablemembrane and said window, a second cavity delimited by said seconddeformable membrane and said window, and focus fluid disposed in each ofsaid first and second cavities.
 82. The focus apparatus of claim 75,wherein said focus apparatus is adapted so that a force generated by atleast one of said first and second actuators is imparted to saiddeformable lens element at a plurality of points spaced apart from andperipherally disposed about said axis.
 83. A deformable lens elementcomprising: a first clamping element, the first clamping elementincluding a rigid transparent member having an optical surface forallowing light rays to pass there through; a deformable membrane; asecond clamping member clamping said deformable membrane against saidfirst clamping element so that said deformable membrane opposes saidrigid transparent optical surface; a cavity delimited by said deformablemembrane and said first clamping element; and a deformable substancehaving an index of refraction greater than one disposed in said cavity.84. The deformable lens element of claim 83, wherein said deformablesubstance is provided by a resiliently deformable member.
 85. Thedeformable lens element of claim 83, wherein said deformable substancecomprises a focus fluid.
 86. The deformable lens element of claim 83,wherein said optical surface is a curved surface having an opticalpower.
 87. The deformable lens element of claim 83, wherein said opticalsurface is a planar optical surface.
 88. The deformable lens element ofclaim 83, wherein said second clamping element is ultrasonically weldedto said second clamping element.
 89. The deformable lens element ofclaim 83, wherein at least one of said clamping elements has an annulartooth ring for increasing a securing force between said first and secondclamping elements.